I will have a few questions about the AI, as you can see, I have not played much yet.
1) Do we know what are the differences between the different levels? Is it only improved intelligence, or is there a resource/gold/research/magic gem (and so on) bonus the player does not have? Dominions AI may not rely as much on bonuses than the vast majority of AI.
2) For the beta testers mainly: is the AI more efficient in the middle and late game than in the early game? Perhaps the AI does not handle well early conflicts, or has trouble with early expansion (compared to an experienced player who tries to expand as fast as possible), or some other problem. Most AIs tend to have a lot of problems in the early game, and some can even be wiped out without much hassle in the beginning of the game. (And then we would have to wait for the full game to see what is the situation after, say, 100 turns)
3) Is there any chance players could alter/make their own AI files? That would depend obviously on how the AI behaviours are handled. There are games in which the original AI has been improved by players. (Space Empires IV for example)