I'm trying to remember, but I think the sharing of personal information is highly discouraged -- I can't remember how strict the filters are, but most players know the rules on personal information. There are certain worlds where the players are limited to a quick chat menu -- similar to the quick chat menu on Toontown.
As far as violence -- yes, you do get to fight and kill monsters, but there isn't any blood or gore. Unless you are on a player vs. player world, you aren't allowed to attack other players, you can only attack computer generated opponents. Personally, I don't fight unless it's part of a quest or I'm trying to level up my combat skills to do another quest. There are lots of skills to level up, including magic, prayer, fishing, cooking and mining, so it's not all fighting.