Supposedly, you can steal Odin's weapon. My theif was no where near level 71 though >_>.

And yea, the thief is pretty strong. When I could first use the thief, he was fighting in the front just as well as the other guys.

And whenever I need to open doors, he still fought just as well as the other guys.

But I don't really use the thief because their defense kind of sucks because of the armor they get to choose from. Also, I like some of the other special abilities more than flee. (not that its bad, keeping defense while running is pretty cool), but I've never had to run from a fight.