OP, is your main class really lvl 43 NIN? Respectfully, I see some points in your post which make me think you haven't played healer at a high level in this game.

General-- We'll have to agree to disagree on homogenization. I like variety. "Let the WHM do it." The opposite is true. In theory, WHM has the highest sustained DPS if it were to do nothing but DPS the whole fight, so you really want the SCH to heal with its fairy and oGCDs while the WHM uses its very, very limited oGCD kit and spends the rest of the time spamming stone. Fun. However, most of why WHM dps suffers in raids is because we have so few oGCD options. We actually LOST an AoE oGCD option and gained 2 GCD heals with these changes.

AST and SCH are so great in part because they synergize really well and have powerful oGCD kits. They also bring buffs. This means not only can they weave heals between damage-dealing skills--heal without losing DPS--they increase the raid dps as a whole. WHM has greater potencies, but that has not translated into higher numbers for WHMs in raids. When WHM got a DPS buff with the assize change, they actually fell even more behind the other healers in personal DPS contribution.

WHM: The pDPS increase would have to be astronomical to make up for lost rDPS from buffs. This isn't my opinion, it is a fact based on tens of thousands of logs. This was not addressed. About Misery, here's another place where inexperience plays in...WHM has a 60 sec oGCD heal and a ST shield, in addition to whatever your cohealer brings. With intelligent oGCD usage between you and your cohealer, you almost never need use a GCD every 30 sec. If you had to choose between using your GCD Afflatus ST heal and your cohealer's oGCD or your own Tetra, it's an easy decision. So it's likely a dps loss somewhere other than a training dummy. Also, unlike AST and SCH, WHM still has no way to weave without clipping. They also don't have much to weave, which is the other issue.

AST: I actually think the new card system is fine. Most of the time you were dumping trash cards and fishing for a balance. Now you use more cards and juggle seals. AST has a mini-game to play while SCH heals. You don't address the biggest change to AST--the CU change. That's huge, I don't see how it was necessary, and it's a hit where AST really didn't need one IMO. The instant application of the heal for CU was a great change. Now they get only sadness.

SCH: SCH dps took a big hit, but their healing kit is buffed massively. SCH is going to be the undisputed king of healing, and I'm genuinely curious how anyone (devs) thinks this is balanced. Not doing anything with Selene is a head-scratcher, and I think a missed opportunity. I feel for my SCH buddies, but I would sacrifice Alpha for a heal kit like they have.