I guess it is the style that I play, but fights are a pretty common thing at some of the gigs....99% fueled by alcohol driven idiocy, and sometimes, mosh pit idiocy... I can't even count how many times the stage has become the pit and vice versa. I guess I have just gotten used to reading the vibe of the crowd, and learning how to defend my self. I have never been in a fight myself, but have had to break up, corral, or distract people in that situation. Usually, comedy from the stage, and eye contact with bouncers nips most things in the bud.
There is usually more conflict/issues during load out in many of the places since they are not always in the best parts of town, but again, I have been really lucky to have not been hurt bad.