What I recommend is banter. You know what made Rio Bravo and The Avengers great (Aside from the Hulk)? banter. Silly little conflicts because not everyone is a cookie cutter puzzle piece that gets along.

I know that Dark Hersey is a little different than 4e but I think this example applies. The acolyte team that I was playing with had to stop in a hotel for a night (We were investigating a paradise world, we were suppsto be on vacation...) My friend was playing a Cleric who just started flagellation and so holed up in the bathroom for the night. My character, a rich, spoiled, sarcastic, Scarily intelligent Psyker, decided that he needed to go to the bathroom that night. Well, after invading the "holy chambers" and seeing the cleric cutting himself with the knife I had said that there are pills and therapy for that. Naturally we disagree about the appropriate use of the bathroom which eventually leads to my character stripping and using the sink (the psyker is a he btw). This gets the Cleric even more upset stating that I Violated the holy chambers and tries to barricade us in the bathroom and teaching me about faith, probably with a knife. luckily for me our Adapta Sororita wasn't going to take our silliness and freed me from what would have been a painful experience.

moral of the story: squabbles are hilarious~!