As far as sunglasses are concerned, most person to person communication is non-verbal, and eye-to-eye contact is a part of that. I don't want to be perceived as this guy,
so, I take my sunglasses off (when I remember...
).
As far as how I am addressed, I prefer to keep a demeanor of approchable yet professionial. In most games, it doesn't really matter that much, but in certain games (e.g. between rivals, in the high school playoffs, in championship tournaments), appearing to be too familiar with one side and not the other can lead to issues.