Here is my take on the game. I have had it for almost a year. I am so in love with it and here is some info on your questions and more.
1. Hand Holding. Nope. You have to use your brain and pay attention to what NPCs tell you. There are often multiple ways of doing things also. Since it's up to the player(s) to be good or evil.
2. AI. The AI is pretty intelligent and will use ground effects and other effects on the players party. Classic Mode is the hardest mode and super fun and challenging, While Explorer mode is a bit more relaxed. From what I have seen it doesn't change their stats, but how they approach battle. Also in classic mode I have had AI enemies stalk my healer even if she was in the back.. so it does seem to identify who is the most threatening or valued.
3. The RPG Element is mind blowing! you can pick your origin. Like my character was a Mystic origin and had special dialog options with some NPCs. I don't know how to post screen shots.. but I will list the selectable Origins. you can pick two.
-Soldier
-Scholar
-Outlaw
-Noble
-Mystic
-Jester
-Barbarian
4. In one of the Co Op videos it shows that party can be different. So you can have goody goody and super evil in same group.
I saw replayability brought up. The game might have a high replay value.. IF they do the creation kit better this time.. the former kit for the other game was horrible and hard to use. Also there is GM mode ~ so we might see GMs looking for players on the forums. Oh Oh and if we can mod the main campaign ~ might see even more options!
