This is what I would like.

Red Mage would be dps support. I like the idea of mixing jobs, mainly cuz I'm not sure this could come from a class we already have. Or they could just add a one handed sword user base class (why isn't there already one?) and have red Mage be the job.
Add a class called thief and have ninja be the job. These would be dps.

tank would be samurai and be similar to auron in ffx and the class in ffx2.

Dark knight would be a melee dps as well. I would stem off of dragoon maybe since they use scythes. Unless they use a two handed great sword like in ffx2.

But most of all I want a gun class. Let it be the musketeer that uses the guns that merlwyb has and the job would be gunslinger and they would use dual magitek pistols.

The reason I say this is cuz as of right now there is only one disciple of war ranged option. All other types have two to pick from. Two tanks, two ranged disciple of magic dps, two melee disciple of war, and two DoM healers.

Ps. I really want a DoW healer like dancer maybe since alchemist can't be it. Unless they make engineer a healer that uses magitek gadgets or something.