What about the idea of social points?
Also the type of missions I'm thinking of would involve things like a Jedi Master/Knight(doesnt need to be full fledged master) going back to Tython to teach a class and train/duel with padawans(this could include padawans controlled by other players). I'm sure that there are other class specific things that can be done and dont need to be huge quest chains, just small class specific things to do along with or after the class quests.