A vital member of any gaming group is the person who defuses any intra-group conflict. This applies both in-character and out-of-character. While in-character bickering can be amusing (see the X-Men or Avengers movies*), there needs to be someone who can put a lid on it in times of crisis when the group has to pull together to achieve a major goal. It can also wear thin easily, so remember that if it stops being fun, just drop it.
Player bickering is more serious, and has to be stomped on quickly. It helps to have someone good at interpersonal relationships in your gaming group. Someone with excellent emotional perceptiveness and social skills. In your group of nerdy friends... Yeah, quick, recruit someone!
* Actually, the X-Men and the Avengers would both make brilliant RPG campaign settings. There have been a few Marvel superheroes games, including a current ENnie award winning version. Maybe check it out.
Obi-Wan: I'm not quite sure where I should be going here.
Obi-Wan: So what should I do?
R2-D2: Well, that's something you really need to start figuring out.
Obi-Wan: Okay. Say it.
R2-D2: I have no idea what you're talking about. Nor do you have any idea about some other things I could mention.
Obi-Wan: This is so none of your business.
R2-D2: Sally's been lying to your parents for you for three weeks! When are you going to make a decision about your life?!
Obi-Wan: I did make a decision. I changed my life.
R2-D2: To what!? Nothing! You're lazing around here avoiding your responsibilities! Sally needs a role model!
C-3PO: I don't need a role model! You need a role model!
Han: Hey, guys, you know what has two thumbs and is the best role model around?
Obi-Wan: A role player is not the same as a role model.
Han: This guy!