Some things that I think would be pretty cool in the modpack, I will keep this updated with suggestions/thoughts as they come through.
increase time between meteor strikes by default. having kittens/meteors on day1 is not cool, possibly even disable kities completely, and increase time on meteor falling by quite a bit, or even relegate meteors to night only. Fixed in 1.01
set minimap to square by default. Circular minimap looks wrong as not enough chunks are loaded by default to generate a proper image. When exploring 1 edge is always black at the minimum, usually 3.
Get more materials included to be available into the TinkersConstruct (and disable normal tool recipes). It might be a bit of a push for new users, but a simple toggle option for something like this would be awesome. 1.01 added NEI items.
BetterStorage/Backpacks both give backpacks. Disabling backpacks in betterstorage would be best by default so there isn't confusion on these.
An HP increasing mod would be cool, such as using experience to purchase different skills. rather than relegating all progression to strictly items, some form of character advancement that can't be lost by dying would be very cool.
xrelinquary - guns are enabled. Why oh Why?!
Fix TConstruct tools not working with TreeCapacitator - Should already be the case.
Get TConstruct to add the book recipe items as pop-ups from a hotkey that are unlocked. Rather than from a book item.
I'm really not a fan of the Dimensional Doors and battletowers mods, I don't feel like they fit the adventure/rpg aspects as well as they could. BT seems more like an arena minigame, and while cool.. not really for a dungeon diving mod. Dimensional Doors seems cool, but it seems like it's just a cheesy way to bypass the meteor events etc.
Overall great job. The modpack has a great feel, and I'm looking forward to seeing additions, improvements, and fixes as are most likely already in the works. Keep up the good work guys ;)