If your expecting a mage to be a healer that should be discussed beforehand. I try to heal when I can but focus on damage.

Most annoying is people who die and expect me to go into a mob of 10 to revive them because they were biting off more than they were able. Or when a lower level person dies 20 times in an hour. At some point I just want to ignore them and play my game(I never boot unless there is a leacher who does nothing, even a low level can assist if they are smart)