Not to rain on the OP's parade, but job fixes, revamps and redesigns should come before they even think of adding more jobs to the game.
That said, Chemist would make sense if it used a similar scheme to NIN's reliance on items (of course, with ways to easily obtain said items outside of the AH). I would want to see them focus on using guns, but more akin to the skill level a THF has with crossbows when compared to a RNG.
