[andrewas]

you can finish the game w/o any chars at all. you could even kill imoen, but i suspect that would break things in the journal. even then it'd jsut be entrys that dont make sense rather than game-crippling bugs. the cutscene outside irenicuses dungeon already demonstrates that you cant affect the plot(put armour on her and cast silence. she will still throw that damn magic missile), and the imoen in the dreams is just an avatar of whatever weird part of you is talking to you.