While I know the addition of new classes and jobs is far, far away, given that there's already a handful on the table for 2.0, I figure it never hurts to discuss ideas. Given SE's track record for listening to the players with XIV, maybe something might come of it. The idea of an engineer class has probably been brought up before too, but I figured I'd give it a go anyways.
So, we have various types of DPS classes at the moment. Everything from extreme close range with Pugilist, to a moderate reach with Lancer, and ranged with Archer. It's safe to assume that Musketeer will take over for the main ranged DPS class past 2.0, but what about the possibility of a jack-of-all-trades type of class? One that can use both ranged and melee efficiently, but not excel at either. A class that wouldn't put out as much power as the others, but be able to adapt to certain situations in combat on a whim.
An Engineer class seems like the perfect fit.
Lore is already established to make sense of such a class. We have the Garlond Ironworks, who could basically act as the classes guild. They're class quests could revolve around the inner workings of the Ironworks. The class itself could wield a Gunblade. They could equip ammunition in their ranged pouch, and depending on their current range to the enemy, their auto-attack would switch between ranged and melee.
They could have various DPS, and even support abilities given the nature of an Engineer. Flash bombs to blind enemies, grappling hooks and wires to tie up and slow down enemies. Their actual DPS abilities would be also be somewhat limited, given the fact that half would be ranged and half would be melee. Combos could mix between the two, giving the class that extra edge of having to position themselves in various spots around the battlefield in order to chain them.
It's probably just a dream that will probably never come true, but I can't help but think that a class like that might help pave the way for more intricate classes and jobs in the far future. Plus I've been drooling over the concept since we first learned that Magitek exists in FFXIV, and not just in Garlemald.