There is already a feedback for this idea, as the other has more likes on it, I will close this one down and ask that you go to the other for this idea :) 

If there is a troll or bad behaviour in chat, you can always contact a member of the staff team or prefect team, or even an AT - there are a few choices who can help out straight away. It is just as easy to look up on the map to see who is around. Also quite a lot of the time the staff are dealing with it, just maybe have not come into chat yet :) 

Nicknames could be the same as other people's. Also, most users have more than one nickname, so it is best to use their full name when tagging so you make sure you get the person you want :)