What's next in jobs?

I personally think there's nothing after pirates. Then again, Im also a person who thought that there'd be nothing after the four primary classes >_> Alchemists sounds like a good guess.

No idea if this is possible, but would it ever be possible for us to get a GMS/Maesteria exclusive class? xD

Well, I doubt we could construct an entire class but I certainly wouldn't say GMS exclusive skills are out of the question, seeing as TaiwanMS invented "Follow the Lead", which is the skill that allows Multipet. I have no idea what such a skill would be like, though.