They could just adjust the stun for a 1.5 second cast time. I also agree lilybell should be on a shorter cooldown.

As for the tetra and assize charges, I'd rather that they rework them in a way that's unique to white mage. For example, I like that assize has damage on it, compared to celestial intersection (if that's what you call it). As for tetra, I'd just add a regen/mitigation on it, and make it feel like equilibrium.

But let's say they did decide to go with charges, I'd probably overheal more than I do right now. Even with the worst teams, I currently find myself overhealing with a lily followed by an assize.