Ragnarok Online has always been on my list of non violent MMOs. Yes it's 2d but almost everything that I've been looking for in an MMO is there (pets, the jobs, the monsters, boss hunts, etc.). I dunno if you played that already. If not, you can always give it a try.
I'm also playing (and currently hooked in) Uncharted Waters OL so I also suggest that. Got to agree on the posters above though. At first it's kinda hard to navigate and all but once you get the hang of it, it's so much fun. Also Dragon Nest (well I haven't been in the game but according to my friends, it'a a good one).