Honestly, both of these jobs wouldn't work.

For Geomancer, the element of the attack based on the environment would only be for the aesthetic since the element wheel is near non-existent in this game. I can see it ending up like Conjurer and/or Thaumaturge but with more ground AoE spells similar to Shadowflare. I'd rather have something more unique in gameplay than unique in aesthetic.

Blue Mage would be super butchered since Jobs in this game are designed to have a scripted set of skills that's always used (with a few barely used but they're only about 2-4 for certain Jobs and depending on the level). You won't have any freedom to choose what skills you want.