Red Mage looks like a dope class. I like the re-imagining of the rapier, and how it can be re-constructed into a staff. Depending on what the other classes end up being (c'mon DPS Samurai), I may be switching to RDM.
Swimming in Stormblood:
I'm not sure how I feel about swimming in an MMORPG. Unlike flying, it was confirmed that swimming will be slightly slower than sprinting in the game, so it may seem boring after a while. Interesting that swimming is being introduced for Ala-Mhigo. I don't instantly think water when that city-state comes to mind, but in reality, it lies nearby a coast:
I assumed that they were saving swimming for a later expansion taking place in the homeland of lalafells, a group of islands in the southern sea (guessing it's those islands south of Ala-Mhigo).