Red Mage

[Seku]

Small issue here...
FFXIV at the moment is setup with healer/tank/DPS setup in mind.

the only place there for RDM would fit in would be a healer+support role (sorry just don't see SE making this a DPS role) like BRD is a DPS+support role

You must have only played RDM in normal parties and never taken it to anything serious, because it was considered the best tank in the game for a long time in 11 and is why they nerfed it's ability to hold hate and everything else to hell and back when abyessa came out.

Second, rdm can fit into the game quite easily, a DoT job akin to summoner with light buffs, cures, and nukes. Give it Arancist's cross class skills. Done deal.