Oh I doubt it would be all of us doing a collaboration at once, that would be hectic! I mean when two (Maybe three?) characters are in a dialogue heavy bit when they talk to each other collaborating might be best, if the group is doing something and they need to talk you can throw in shouts or a few lines easily. It just means we will have to be aware who is posting when so as to not clash. That and possibly combat, but for that you will most likely be splintered, I also think that I will be controlling the main bad guy in each fight but there will most likely be grunts etc which I would just let you all run with as controllable NPC's if that sounds cool to you all? Just remember to keep it realistic.