I think Chemist would make an awesome new job, they did exist in a few older FF (FFT comes to mind), and they could work around tossing items party-wide, and they could have items only their class has access to, making it a very versatile class, as in half healer half buffer for great effect.

It could also make some dangerous mixes, such as venoms and acids to toss around and tag mobs.

And probably its more important skill would be something called Salve, where you could use 1 item (they could introduce newer healing/buffing items into the game), party wide, with a moderate cooldown to offset the possible OPness, depending on the item used.

It could very much restore MP also to single targets. All of these balanced of course.