Things I've noticed so far:
Karma is a valuable commodity, and is able to... uh, um... okay, it doesn't do anything and I don't understand it at all. I'll +k people(I don't care enough to -k) and accept karma, but I don't really know why. What are we doing!?
People take this game way too seriously. Half of Mafia is about deception. The other half is whining about the players involved and acting out a superiority complex to off-set a likely inferiority complex in the real world.
If I am tracker, doc or cop, I will be killed on n1 nearly every time. There's probably an official rule for this somewhere.
My teammates will not always be correct on a 3 lynch, as can be expected. Interestingly enough, freaking out at them and -k'ing them for an incorrect assumption doesn't cause me to win a game. It makes me look like a dick(See #2).