I actually had a thought about this a few days ago and made a note on my phone. Here's my take:

White Mage: PvP skill seraph strike is now in PvE. It can be used whenever you have at least one stack of sanctity. Any non-lily GCD heal grants a stack of sanctity. 1 stack of sanctity, SS deals 280, 2 stacks 560, and so on up to four stacks.

Sage: Toxicon's potency is now 660. E. Diag still grants a sting as it does now. Diagnosis grants a sting if used on a party member below 60% HP. E. Prognosis grants a sting if four of the barriers applied by E. Prog break. Prognosis grants a sting if at least three party members healed were below 60%.

Astro: New effect on combust. Any time you use a GCD heal, your combust explodes on the target and deals damage to them equal to one cast of malefic.

Scholar: Miasma 3 is back. Any time you apply shields you get a buff which increases the damage of your next miasma 3 equal to the potency of the broils you didn't cast. So if you used two adlos, you'll get two stacks, your next miasma 3 will deal extra damage equal to two casts of broil. If you use adlo, you'll only gain a stack if the person you shielded didn't already have a barrier from you. If succor, only activates if four or more party members didn't already have a barrier. Stacks 3 times.