the fee is about $10 a month. Goes to maintain the servers, work on game development and stuff. I'd be pissed about the fee if I didn't feel I was getting anything, but the guides and GMs are really good about being there, and the game is constantly evolving.
it can be addictive, as can anything that's a lot of fun. The developers realize this and have built in an alarm that you can set to remind yourself when you need to stop playing and do something else.
There's newbies on every server. Finding groups isn't a problem. Just pick a class people want to play with (enchanter, cleric, warrior, etc)