I like it a lot for single target.

Some nitpicks:

Would it be worth condensing Banish and Ablution down into a one button combo as well? Having the two on separate buttons feels sort of needless to me if I'm understanding the flow of play right.

In light of the above, losing the big potency bomb from Misery is a bit of a shame in my eyes, it's a satisfying ability to use and a rare dopamine hit for healers as is, would it be worth dropping some potency from Banish to get Misery back to it's current value?

It's out of the remit of the post but it would need some expansion on multi target for sure, multi dotting on pull and getting value out of those big potency Miseries is the core of WHM aoe gameplay and this removes both of those facets. Perhaps something like Purgation adding a bane effect to a Dia'd target turning the Banish>Ablution cycle and Ruach into aoes?