A few suggestions for WHM
Instead of Esuna's lousy "potential free cast" nonsense, make Esuna cure a buff and potentially add a status resistance buff for idk 10 or so seconds making the target immune to debuffs. Chance shouldn't be too rare for it never to happen (like esuna) but not too common that is overpower some mechanic (could be negated by boss-mechanic debuffs like Ultima's stacks on tanks). Chance: 40%. Cureable debuffs would be resisted (poison, attribu down, sleep, etc)
Cure III: Additional trait, resets buff timers (or adds a specific amount of time to them). It costs a chunk of mp and is very situational. I pretty much Medica II/I over this every time since most of the time I'm dealing with raid-wide damage. I know this would make Cure III pretty amazing in other senses. Perhaps this could also be a "chance to proc" skill. I think with would be great as an alternative to prolonging regens/other buffs. Since atm I was thinking this could only reset regen buffs, there may (or may not) be arguments made for resetting other buffs.
That was pretty much it.