I'd personally like to see Chemist instead of engineer. I think this has actually been said multiple times in this post. An extra healer would be really good for FFXIV. Not to mention the idea of throwing a potion in the air, shooting it, and having it heal your party? Pretty cool. The Chemist could also have bombs, status effect potions that he could throw at the mobs (kind of like the thf bolts in FFXI) etc...

That being said, it doesn't really fit in FFXIV in terms of Eorzea persay. It fits well with the Garlean Empire. Doing some sort of sleuthing to get the job.. would be neat.