The ugly truth is that the common stereotype of DJs, for most people, is that we are by and large an egotistical, somewhat bratty, fairly elitist bunch. How applicable that stereotype is should definitely be up for debate, but the really funny thing is that this is the exact same stereotype for any musician with a “rockstar” persona, and nobody you’ll be working with likes it or has any fucking time for it. Ever. Even if you’re a good enough DJ to be touring or playing out-of-town shows, nothing will earn ire from fans, promoters, and really anyone you encounter faster than being an asshole to the people you work with.
If there’s a problem at your gig that is outside of your own control, or something that is not your duty to fix, just let it go and let the appropriate venue personnel deal with it. If they can’t deal with it or try to blame it on you, learn how to walk away from it and get terse only if you’re being picked on… but whatever you do, stay the bigger person whenever possible. Sometimes you have to put your foot down and tell the people paying you what's up if you're being treated unfairly, and be ready to accept this means you may not get paid, but it's important to establish that you deserve fair treatment as a professional providing a service for a fee.
It might seem silly in the short run, but having a widely-recognized reputation of being the DJ who is friendly, professional, and consistent gives you a tremendous amount of sway in the long run, which of course translates to myriad other job and money-making opportunities for you.