My problem with permanent DoTs in raids is that's just going to elicit or validate permanent medica 2/aspected helios which feels kinda like healing for the sake of it to me. Having more DoTs in general though is something I would support, similarly in addition to raising damage by perhaps 50% for raidwides increasing the frequency of raidwide damage by perhaps the same amount. I've seen people talk about frequent but not lethal and I like it. I agree with 75-100% or maybe more tank damage, tankbusters should have the capacity to be lethal if not properly mitigated and auto attack damage is a joke throughout the entire game. Also whatever happened to tethers?

I'm not sure I like the idea of losing my oGCDs though, as a WHM, more often than not when I use oGCDs it's in conjunction with something else or where I'm healing two or more people so I can cast a GCD heal for one and weave tetra for the second and so on. I know AST and Sage have more oGCD options and maybe giving them some drawbacks, especially in an increased sustain damage environment would make them more situational or supportive to another solution. For example if AST had only regen or delayed heal oGCDs, it wouldn't necessarily outheal all the damage taken over the duration or address an immediate situation, forcing you to supplement them with something else or hope your co-healer coordinates with you. To that end, I would suggest that GCDs (especially casted GCDs rather than instant) should have higher potency simply by virtue of you have to stand there and cast them.

SCH's oGCDs are a slightly different matter since half of them are fairy skills that it makes no sense to have become GCDs except maybe in the fashion of WHM's lilies, which actually gives me another idea, I've pointed out previously that tank gauges are underutilised, maybe it's worth considering making healing oGCDs cost some resource other than time.