Ok. Icewind Dale works now BUUUUUUT...

Every time my friend talks to someone it interrupts me and vice-versa. How do we stop this? If my friend wants to get quests cool but I don't want to deal with that when I'm trying to shop, steal, walk, fight, whatever.

I'm pretty sure that is a part of the game mechanic; you can't stop it from happening. I know it's a bit pesky if one of you is shopping etc. but the best thing to do is coordinate so that he doesn't initiate a conversation while your in a shop, or vice versa.

Every Infinity game works this way, if I recall correctly.