More succinct version of my earlier post: DPS meters and UI customisation = bad. Some people might be OK with them, but giving assholes an enabler to let them be bigger assholes is never a good thing.
Tune the content smartly, encourage server communities so people will be held accountable on that level, and don't give elitist, rude people the tools to impose their mindset as THE WAY IT MUST BE DONE!!!!1!.