redsector

The tooltip on the top is from the WAILA mod. Default key to toggle it should be Numpad 0 unless the pack author changed it.
As for the one on the left, no idea. It's definitely not from Tekkit.
 

And if you're like me, and hate sieving through videos to find useful information, you can also >read up on the basics.

For multiblock liquid storage, try Dynamic Tanks 2, a very lightweight (and supposedly lag-free) tank mod. I added it to Tekkit myself because I was sick of tanks only stacking vertically, and it works perfectly. I was going to suggest it to the modpack authors as well when the time is right.
 
As for Biomes O'Plenty, it works fine with Mystcraft, the only problem is that you're going to find dozens, if not hundreds, of biome pages for every other feature page, simply because there will be so many of them. That said, I added BoP to my Tekkit, too (together with Alternate Terrain Generator), and I wouldn't want to play vanilla worlds anymore. The sheer beauty and variety (and sort-of realism, if you configure it accordingly - no jungles intersected by ice plains or something like that anymore) of BoP+ATG worlds compared to vanilla worlds is mind-blowing. It is quite resource-heavy, though, that's correct. My computer can easily handle it so I don't care, but it might indeed be unsuitable for a balanced pack. For a little more variety in world generation, though, there are smaller biome-enhancing mods like Highlands, which might be worth a try.

Since adding Forestry technically turns your Tekkit into a custom modpack, you probably should have posted this in the Platform Pagoda section. I'll help you out anyway since there's really not much to it, but posting in the wrong section is heavily frowned upon around here, so keep that in mind.
 
Anyway, you just have to change some of Forestry's block ID numbers since they're already used by other mods (Extra Cells and Extra Utilities, in this case). The IDConflicts file makes this easy for you by suggesting unused IDs at the end ("Suggested Ranges"). So, open the Forestry config file (config/forestry/base.conf) which contains the ID infos and find those blocks listed in the error log, then change their number to something else within the suggested free ID ranges.
 
For example, change "I:mail=4086" to "I:mail=2530", "I:factory2=4087" to "I:factory=2531", "I:engine=4088" to "I:engine=2532" and so on until there are no more conflicts. Simple as that. If you're running a server, keep in mind that you'll have change the config file for both the client and the server.

Another tip concerning the assembly table: Like all Buildcraft machines, the laser(s) will keep sucking power out of your network even when idle, and they cannot be switched off via levers.
 
So you might want to consider putting an energy cell (any will do, but I would use at least a Hardened Energy Cell - the 80 RF/tick limit of the Leadstone Cell would make the laser even slower than it already is) between the laser and your main energy network, attach a lever to it and set its redstone control accordingly, so you can cut off power to the assembly table when it's not in use. You'll be wasting a lot of energy otherwise (of course, if you have something like a Big Reactor already running and producing excess energy, you probably won't care).
 
(FYI, switching off power can also be automated via Buildcraft pipes, logic gates and the "machine has work to do" condition, but that's probably too complicated to get into right now, so just go with the manual switch off method.)

Assembly tables cannot be powered directly. You need to build a laser and place it somewhere facing the assembly table, like this, for example:
 

 
You can place it above the table or sideways, however it fits best. Then connect power to the laser, put a piece of redstone on the table and the laser will start crafting your chipset. Make sure to put a chest next to the assembly table, otherwise the crafted items will simply pop out into the world. Apparently, the thing does not have an internal inventory for finished products.
 
You can use multiple lasers per table to speed up the crafting process.
 
 
Edit: AetherPirate beat me to it

Don't worry, those "sacred" rubber saplings you get from cutting down regular rubber trees are fake and won't actually grow into that gargantuan rubber tree. The real sacred rubber saplings are only found in jungle temple chests.
 
If you're interested in technical details, have a look at the item ID of the sapling and its meta data (the number after the colon), which should be displayed in the NEI tooltip. Regular rubber saplings are ID 698 without meta data (i.e. just 698), the real sacred saplings are those with a metadata of 1 (i.e. item ID 698:1), and the fake saplings have some other number as metadata. Can't remember which exactly, but as long as it's not 1, it's a fake sacred sapling and safe to plant, it will behave like a regular one.
 
(On the other hand, I remember reading in another forum that some dude actually took the time to harvest that massive rubber tree thing and ended up with something like 2-3 million pieces of rubber wood and raw rubber, and more than 100k saplings. So if you never want to farm wood and rubber again, go ahead, find that real sacred sapling in a temple, plant it and set a massive array of harvesters to cut it down. Expect it to take days. )

No idea, but I guess it's intended and meant to troll players. If it was a glitch, it would have probably been fixed by now.
 
 
 
That's what Deep Storage Units are for (2 billion items per unit). Or a massive AE network.

Craft yourself a Mystcraft Writing Desk if you haven't already, and some notebooks (3 leather in a V-shape). You can store the notebooks in the writing desk and organize your symbols in categories. And you'll probably need the writing desk anyway if you want to get into writing specific ages yourself instead of randomly generated ones (while you can assemble the pages you found to new age books in the book binder, the writing desk lets you copy them so you don't run out of those pages you use often).
 
You can read more about that here. This Mystcraft wiki is actually a good source of information because it's maintained by the mod author himself, so the information you find there is usually up to date.
 
Oh, and you may also want to have a look at this, this and this, too. Those are guides for understanding the Mystcraft grammar system and a few tips for writing ages exactly how you want them without any instability, randomness and other unwanted stuff.

Every Mystcraft age, whether generated randomly or to specifications, has page libraries scattered all over the world. They're rectangular stone structures, about one chunk in size and 15 blocks tall, not really common but not too rare either, and easily spotted on the map (use the large map by pressing X). These libraries have lecterns containing feature pages (randomly selected, not related to your current age's features), and there's a hidden chest among all the bookshelves with a rather large number of pages as well, or sometimes a notebook filled with even more pages. And before you ask, no, you cannot extract pages from randomly generated books.
 
Here's a pic of such a library:
 

Nobody's calling you an idiot, but I guess you did, in fact, not look hard enough .. I mean, actually reading all three pages of this very thread you posted in would be a good start, seeing as its creator CXXIVLDIVL had pretty much the same problems as you. Also, >Curunir's newbie tutorial answers most of those, and there's the wiki to help you out if you're looking for something specific.
 
If you absolutely need guides in video form (sigh), make sure they're for the current Tekkit version. Those you watched are outdated, things like electric furnaces and batboxes are from Industrialcraft2, which was kicked from Tekkit quite some time ago (it's still in Tekkit Classic, but that's not recommended unless you're feeling really nostalgic). Most machinery stuff is covered by the Thermal Expansion 3 and Minefactory Reloaded mods now. TE3 also handles basic energy generation via dynamos. So you can search for guides on those specific mods if you just want some tips on starting out and don't need or want the entire Tekkit experience laid out.
 
As a general rule, if whatever help resource you're looking at is older than mid-2013, it's probably for the wrong Tekkit version.

Find a village and trade with the villagers for emeralds. Some of their trades are quite favorable in terms of exchange rate, like 10 raw fish for one emerald. Or a bunch of coal, wheat, wool and other easily farmable stuff.
 
If you want to mine them, you'll have to do so in Extreme Hills biomes, they only spawn there. Y-Level is about the same as for diamonds, i. e. 16 or lower, I think.

"Item Frame" is probably what you're looking for. They're a vanilla item.
 
 
Or, if you're not afraid of adding external mods to your pack, you might want to have a look at BiblioCraft, which offers a whole lot of decorative stuff, including little wooden labels that, imho, look even nicer than item frames.

Probably. But why the hell would you worry about that? As long as there are only minor Tekkit updates (such as 1.2.10 as an update to the current 1.2.9), I'm pretty sure nothing will be entirely removed. So there's no problem unless you decide to delete mods from the package yourself after already using their blocks in your world.
 
And after a major update, i. e. when Tekkit finally makes the jump to a new Minecraft build and some mods might indeed not make it into the final package, you'll most likely have to generate a new world anyway. Big updates like that have a tendency to mess up existing worlds from earlier minecraft versions in a number of ways in addition to the whole "missing blocks from older mods" issue.

You seem to confuse Tekkit and Minecraft version numbers.
 
- 1.2.9 is the current stable TEKKIT version, 1.2.10 is the current Tekkit beta. Choose whatever you want in the launcher.
- 1.6.4 is the MINECRAFT version the current Tekkit is based on. You cannot change this, the pack was made for this Minecraft version only. Updating to a newer Minecraft build would require new versions of every mod. The modding community usually stays one or two major Minecraft builds behind, as those are usually stable and mostly free of bugs. That said, the transition to Minecraft 1.7.x is currently underway, so once it's supported by all required mods, you can probably expect a new Tekkit build some time in the, uh, not-too-far future.
 
 
Oh, and about your sprinting issue, try double-tapping your forward movement key. Works totally fine in 1.6.4.

If by "pinpoints", you mean your map waypoints, those are saved client-side, as the minimap is a client-only mod and technically not part of the server. They're saved in your modpack folder in ..tekkitmainmodsrei_minimap as *.points files and their names are both server-specific and dimension-specific. So, for example, if my server's IP was 212.32.101.94, the waypoints file for the Overworld (dimension 0) would be called 212.32.101.94.DIM0.points.
 
The fact that it's all client-side makes me wonder why you lost them in the first place. Did your server IP change? In that case, you have to rename the various pointfiles accordingly. If you installed the new client in a different folder, just copy over the files from the old client.

When I started fiddling around with MFFS, I couldn't (under-) stand the weird distribution mechanics and operation modes of Fortron Capacitors either, so my ultimate solution was to simply not use them at all. Fortron is a Forge-registered fluid and can be pumped around using fluiducts and tesseracts.
 
Leaving out the Fortron Capacitors makes the entire system a lot easier to use. All you need to do is feed power (RF) into a Coercion Deriver which will convert power into fortron at some fixed rate that you usually don't need to care about, maybe pump it into a storage tank if you want some kind of buffer, then use fluiducts to transport the fortron to its respective consumer device (Interdiction Matrix or Force Field Generator). No need to worry about frequencies, filling mode, distribution mode, emptying mode or whatever you can set the quirky capacitors to. As long as you're producing more fortron than your end devices are using, their internal fortron tanks will first fill up, and once the'yre full, the Derivers should regulate themselves to only produce as much fortron as your devices are actually consuming (i.e. they'll simply consume less RF). No need to worry about kL or whatever units it's measured in either, though keep in mind the 200 mB/tick limit (or was it 120 mB/t? can't remember) on fluiduct connections which may become bottlenecks at higher fortron consumption rates. I can't remember the conversion rate between kL, mB and RF right now, have to check ingame when I get around to it.
 
It's probably not exactly how the mod authors intended us to use their machines, but hey, it's not our fault if they're not providing any useful documentation about the inner workings and mechanics of their mod.

When I started fiddling around with MFFS, I couldn't (under-) stand the weird distribution mechanics and operation modes of Fortron Capacitors either, so my ultimate solution was to simply not use them at all. Fortron is a Forge-registered fluid and can be pumped around using fluiducts and tesseracts.
 
Leaving out the Fortron Capacitors makes the entire system a lot easier to use. All you need to do is feed power (RF) into a Coercion Deriver which will convert power into fortron at some fixed rate that you usually don't need to care about, maybe pump it into a storage tank if you want some kind of buffer, then use fluiducts to transport the fortron to its respective consumer device (Interdiction Matrix or Force Field Generator). No need to worry about frequencies, filling mode, distribution mode, emptying mode or whatever you can set the quirky capacitors to. As long as you're producing more fortron than your end devices are using, their internal fortron tanks will first fill up, and once the'yre full, the Derivers should regulate themselves to only produce as much fortron as your devices are actually consuming (i.e. they'll simply consume less RF). No need to worry about kL or whatever units it's measured in either, though keep in mind the 200 mB/tick limit (or was it 120 mB/t? can't remember) on fluiduct connections which may become bottlenecks at higher fortron consumption rates. I can't remember the conversion rate between kL, mB and RF right now, have to check ingame when I get around to it.
 
It's probably not exactly how the mod authors intended us to use their machines, but hey, it's not our fault if they're not providing any useful documentation about the inner workings and mechanics of their mod.