Astrologian i'd just completely rework it

Rather have the 240 potency back lol. The cast time it has right now is perfect to manage the stuns, though one thing i would work on would be on the animation time between the cast finishing and the actual stun occurring.

That aside what WHM needs is something done to the traits mainly the trash ones that replaced graniteskin and proshell.

Medica I trait needs a proc like how cure II procs overcure and cure I procs freecure so we can plan medica I use better, it could also be replaced for medica II rather than medica I as medica II plays a much larger role in raids than medica I such as "x% chance of hots proc x% mp reduction on medica II". Though due the low level of those traits this might not be possible without a whole change of the trait system.

Quick stoneskin is just trash, stoneskin without it is almost useless so bringing it back would be the best.

More skills like assize with double effects under cleric, once gain dots under cleric having a % of draining mp would make WHM less tight in terms of mp management while keeping it actively casting. After all WHM is the most offensive healer of all 3 and yet we're punished for dpsing by going oom way too fast.

Raise trait should be removed for all healers and replaced for something actually useful. E4E and virus should also have their traits removed just how proshell and stoneskin was equalized for all healers.

Dissipation should just reduce the fairy power for x duration rather than completely removing her, something like -80% heal power on use and a possible vulnerability debuff so bad management makes her die during dissipation use. After all you're draining her power to yourself.Fairy nerf overall, yoshida already said this is something he's planning to just doesn't know when to do it.

Astrologian i'd just completely rework it. Sects were a mistake, ripping off WHM base toolkit was another mistake. Since they're time themed maybe dots that trigger a cure when the target goes below x% hp or something like that.