(1) I don't see this, and it's hard to argue in one breath healing is more meaningful, while somehow being easier than the current system. Again, the more priority you place on cures over optional DPS, the harder it will be. You're arguing maybe for a different kind of difficulty, and that would have to change a lot more than just healers to be implemented. I think you believe its easier, but it may very well be the same difficulty or worse, because triage just pushes the wipe ten minutes down the line instead of it happening in 60 seconds.
(2) This puts more of a burden on healers to fix mistakes, ironically. Part of the "bam, your dead!" model means DPS need to know they can't rely on the healer too much to ignore mechanics. And also, if this style of play leads to longer fights, you still have more stress; hard fights generally are at a decent sweet spot in time to where you aren't getting exhausted healing over the long term.
(3) Well, the thing is that if you want say 70-30% heals, you are essentially asking people to cast cure as much as stone in a fight, so you would just swap the boredom. Rotations tend to make that somewhat more interesting and probably would end up being made.
(4) The point was not for you specifically, it's more an observation that modest changes people dislike intensely...so then why are people confident they'd be ok with intensive changes? Even good ideas can be poorly implemented, and the devs simply are not going to implement in toto any suggestions here, except in a general way or modest way. I think a lot of these points should be argued for the next game SE makes, unless we are ok with SE constantly changing the base mechanics of this game every expansion, or even more frequently.