[Why are ore depths unlimited?]

Diamond gear is very weak in hexxit, and even when enchanted, it still isn't very good.

I was contemplating playing in Adventure mode, which, if you haven't followed the progress of it, now basically means that you need the specific tool to get the resource. No shovel, no dirt. No axe, no wood. It seems like it will encourage looting and adventuring even more, and keep ore gen from being too powerful.

[Why are ore depths unlimited?]

It was surprising to me at first too, but once you understand this mod is more about exploration, discovery, and gearing up to clean out a dungeon full of hostile mobs and a boss, it makes sense. Diamonds are common, loot in chests is super rare and what you are 'grinding' to find.

I agree with this sentiment, though I think ore generation should be scaled back a bit. Make diamonds, etc in the lower 40. Hexxit may be more focused on adventuring like in D&D, but there's nothing wrong with branch mining in D&D either. IE - I've not seen too many diamonds sticking out of rocks in D&D. Building a diamond sword should be about the same difficulty as getting one out of a chest in a room full of baddies - the gameplay is just different.

[Thoughts so far?]

The empty spawners are scripted spawns. Get out of creative/peaceful and they'll turn into context specific mobs, like specters or pirates.

… so the upside is that this mod provides us players with a very very fun time of thinking up creative ways to tackle the new un-explored dungeons and castles that await.

I've found Hexxit to have some challenging mobs. In fact I'm getting my butt handed to me. But an interesting thing I think is happening: the one-off mobs disappear and it get easier each time. I think my bed is outside of the chunk and when I died I'd run back to the Necromancer's tower. Each time I died fewer enemies were there, after two times the necromancer was gone altogether. Sweet. Now I get his fort. Complete with some weird rift that constantly spawns in endermen.

So it's been kind of easy by mistake. I'm deliberately staying clear of the fortifications so that when I can challenge them it's not so cheaty. I just wish that the context-specific mobs stayed around long enough for me to break their unholy bones.

["Run AppleScript" encountered an error.]

I also had this problem. It works on my user account but not my sons, where this error pops up. I installed another version of this in ~/Applications (in his user folder) and it works fine. So if you have multiple users on your computer and it works for one and not another, try that.