Okay. I have an idea.

What if... (hear me out)

What if we had a job similar to disc priest in WoW? A DPS/healer hybrid class requiring the healer to do damage in order to heal? It would be something new and challenging for the healers who haven't had a new class in years, and it would work just fine as magical melee DPS, too.

Again... maybe something to do with the elements? Fire, Earth, Air, Water, Ice, etc. Weapons imbued with the elements... perhaps something dual-wield like double switchblades or something. Put a HoT on people, then start beating on the mobs to ramp up that HoT. The more DPS actions in succession (with no heals), the higher the heal, and the more heals in succession (with no DPS), the higher the DPS.

Could maybe even allow the player to put themselves in an elemental "stance" of sorts. Spells change based in the chosen stance; each stance has a cooldown before it can be used again - think Bard songs, but with the various elements.

DPS/heal spells changing based on the current Eorzean weather, but only aesthetically as anything else would be too much RNG.

CDs could be situational and the job gauge might fill by doing significant damage. The "powerful" abilities would include both a hard-hitting magical attack and an "oh shit" heal to be used at the player's discretion.

The utility would be insane. It may be difficult to balance, though... needs to be strong enough to manage a 4-man solo, but not so strong that EVERYONE plays it.

It could be called Elementalist and be defined as a DPS/healer hybrid that can be utilized efficiently in ALL content as long as the player knows how to balance it.