I think one of the main issues is the use of elements and your inability to control them.
The only jobs who would benefit from Focalization is GEO, WHM, BLM, and SMN's Pets, and even then BLM and SMN wouldn't really work well together during boss fights, seeing as BLM will want Fire and SMN will want Wind for Garuda. I might recommend instead of lowering an enemy's elemental resistance, maybe grant debuffs the whole party can use? Like Fire could increase damage done onto the target, while Earth could decrease the damage the target could deal, etc.
The weather system wouldn't work well either because what would happen if you got an under-used element like Water, Earth or Lightning? The only jobs that have those respective elements are WHM (with Fluid Aura and the Stone-line of spells) and BLM (with the Thunder-line of spells). I would suggest maybe making an ability that lets you control what element you currently have and maybe cycle through them.
Airbender's description confuses me. It will protect partymembers with in the AoE but not from Raid Damage? So it won't protect from AoEs? That's kind of the main reason we have those bubbles in the first place, seeing as the only partymembers who get attack regularly are tanks.