It's very good, probably best in a Final Fantasy game. However, there are some flaws and changes I'd make:
1. Be able to set AI prior to battle so what buffs/debuffs (e.g. If Enemy fire based > Fire buff else Haste>Protect>Shell etc.) kinda like the Dragon Age/FFXII system.
2. Transition between paradigms should be quicker.
3. Be able to mave the character manually to get out the way of offensive spells/moves.