Honestly I feel like classes match up pretty well with their namesakes. There is little I would change one way or the other, (though BRDs and MCH shouldnt have casting times, imo).

Really though, If there was one thing I would alter slightly, it would be to give WHM a unique ability. I feel that's lacking. Scholar has a pet, AST has the Cards. WHM has.... hmm.

I know people make comparisons that WHM is like PLD, it's reliable at it's job. But even PLD has a shield to make it feel special...

I know healing needs to be balanced so people don't favor one healer over another but... I feel like WHM needs something to set itself apart. Given it's proficiency with healing magic, what if WHM could Resurrect while negating Weakness? Or reducing it drastically? I feel like it would fit well with its theme of "Empowering players through holy forces" kinda deal. And it would make WHM a little more unique. It wouldn't make the class "More viable" than another, because if healing classes do things right, people shouldn't die. It also fits with WHMs current role as more of a "Forgiveness" healer (Also a good name for the move/trait) that can pick up the slack with groups that are learning.

Meh, just a thought...