Solution to bring BLU into FFXIV in another way.

[Nihility]

As long as Blue Mage starts at level 50 you can just start playing with more than half of your spells already learned... >.>

I honestly wouldn't surprised if they took that approach because beyond level 50 all of our new actions come from the completion of quests. In the case of Blue Mage those could all entail fighting monsters, concluding with the player learning how to harness the power of the monster that was fought.

It wouldn't my personal preferred approach, but it would bypass the segment of the game in which actions are awarded merely by attaining a new level. Why address the issue when ignoring it is a viable solution?

job quests would most certainly be how a FFXIV blue mage got blue magics. They could even include the 30-50 ones so you'd end up with 15 blue magic spells
i would imagine the base stuff could be saber attacks and cooldowns and passives

this game is far too structured for it to work any other way