Quote Originally Posted by Lambdafish View Post
A few things to note:
- RDM channels aether through the magicked crystal medium.
We don't know this for sure or not yet. All we know is that the Magicked Crystal Medium is there. Its function is yet to be determined. While I don't doubt your speculation to be correct, there could be any number of functions it serves from drawing minute amounts of aether from the world and mixing it with the Red Mage's aether, to just being the part of the weapon that enables spellcasting. Old lore from 1.0 stated Conjurers needed tools made from living wood to work their magic (wands/staves) and Thaumaturges needed enchanted stones bound to their weapons to work their magic (gems in rods and staves).

Quote Originally Posted by Lambdafish View Post
My theory is that RDM works more like SCH, and is a Sharlayan job which is formed from intense study of aether, using the crystal medium as a way to channel aether, and concentrate it, allowing for massive control over the elements, and their aspects.
I'm inclined to agree that Red Mage is a Sharlayan job given the overall aesthetic and the presence of Sharlayan in the narrative as the defacto Mage Nation of the modern age. There have been theories that Sharlayan was formed by dissident White and Black Mages during the War of the Magi, who fled Eorzea to study in peace. The Red Mage would've been the love child of this union, a combination of White and Black Magic. There have also been other theories that the Sharlayans recently uncovered enough information about Mhach and Amdapor and their arts and were able to create a new kind of magic from that knowledge; Red Magic.

Theories and speculation are fun, but I'm rather eager to learn what Red Mage's actual Lore will be.