For Corsairs, I personally think they're fine as they are. I mean, look at all those crazy mobbing skills. Rapid Fire + Dignity makes them decent at bossing too.

Shadowers...I think the Killing Points charge up a little too quickly at the moment. Maybe they should make each attack charge up half a point instead of a full point. And yeah, Band of Thieves. Shade Split is crappy on NLs, so they really should pass it to Shads and give NLs a better mobbing skill. Come to think of it, how about making Shadowers a skill chaining class like DBs, Mercedes and Phantom?