If I'm understanding right, your point is that (assuming we're on about PF randoms) 'people won't have a reason to take a Damage-to-heal healer like SGE over a more standard style healer like SCH, because there's someone who would prefer to play SCH in the queue'? But we don't take people in PF based on class outside of, as you say, terrible balance (cough MCH) or super-bull-unfun-but-necessary cheese choices (cough P3S AST), we just roll with whatever we get. Heck, even in week 1 prog groups I've been in often don't lock BLM out, they don't care enough about the additional Res. If you know your class, you get in, seems to be the way it goes. So, a more 'technical' healer like a SGE would not see trouble getting into parties.

As for statics, it depends on the level of skill of the static. You know the bell curve meme? I'd think the casual (left) side would say 'play what you want lmao', the middle 'think they're good but actually they're kinda not' Dunning-Kruger players would whine and complain to 'only play the meta' (as they do atm, so nothing is changing), and the super hardcore (right) would say 'play what you want lmao', cos they're skilled enough to make anything work. Heck, there was a week 1 clear of P8S with a MCH, despite both MCH being 'not great' at the time (it's had 3? rounds of buffs since then) AND Heph's HP was nerfed by like 2-3% since.

As for design, while 'organic design' (at least, what I think you're on about) is cool, you have to consider that certain things need to be set in stone designwise, else you end up with weird stuff like 'Fuma is better than Raiton' and 'Fuma-Katon-Doton TCJs are a DPS increase'. The 'features' of SGE, I'd argue, would be the lines on the slide at Fanfest, and Yoshi-P's description of it. Namely, 'Temporarily augments own skills' and 'can heal by dealing damage'. So that's what I used to make my list o' ideas. The 'how' of how it'd augment it's skills, or 'heal by doing damage' would be up to SE to create, but I think there's some versatility in how you'd choose to heal on it. Augments, Addersgall spenders, GCD healing if you're really on panic-mode.

And personally, I wish 'Pure vs Barrier' referred to what they provide, when I heard 'barrier' the first time I thought Virus, Disable, Eye4Eye, etc. But no, what we have is not a distinction in gameplay, nor in what they provide. Pures can provide mit and shields, Barriers can provide pure healing throughput. I guess what it refers to is 'what is available as a zero-CD GCD, shield or regen effect?' But even then, AST presses one button and can suddenly provide both, so who knows at this point? 's why I made that thread, to complain that the split doesn't work, and rather than spend MORE time trying to fix it, I'd rather they just throw it out as a failed experiment, as they did with MT/OT split. Give WHM Stoneskin/SS2, upgrade them to Afflatus Whatever, give AST Nocturnal Sect back, let them swap in combat