I've heard about all of the bugs you mentioned before, although I can't confirm them personally, because I just got the game and haven't really had a chance to play it. I just completed act 1 myself, so I haven't even looked at act 2. Act 1 seems to be completely bugfree however.
The act 3 battlefield problem seems to be pretty big. I'm sure it will be fixed by the next patch.
Tovi 