I've done a bunch of job concepts for stuff like this, especially the Blue Mage one in my sig (#shamelessplug).

Whenever I do a job concept, my goal is usually a moldbreaker. I made my Juggler concept to show that a physical ranged DPS doesn't have to have some fancy projectile weapon and how cast times on a physical ranged DPS should reward the player for standing still rather than punish them for having extra mobility. I made my Saint concept to show that healers don't necessarily have to be a stereotypical robed caster. Right now, my next concept is to show that a spellcaster tank could exist in FFXIV.

The biggest obstacle to all of this though are players who want something from a past game (usually XI) exactly like how it was in that game when they fail to realize that it won't happen because bringing in a job from a past game requires it to be readapted and refitted so that it works FFXIV, even if that means it wouldn't work like how previous versions might have.