i) Ari has done almost an entire tier with scholar/ sage, you don't even have sage unlocked according to your profile and your scholar is still level 80. Unless you have an alt set as your main you have obviously not done any savage or ultimate with a double shield healer so I'm not sure why you felt the need to say "you don't know how they work" . The super awesome cooldowns you list have assigned spots they're used, so for some weird reason you can't use pneuma or spreadlo on the go if people go full headless chicken mode while they're still on cooldown. White mage can use cure 3, astro has helio and sage/ scholar have a single use of their ability that turns the shields into direct heals after which point you just spam your shield. If we're talking about recovery mode because people failed mechanics and you can't burn one of your pre-assigned cooldowns to save the run, white/ astro are just superior at that.
ii) Again, you list off cooldowns but not only are they already assigned, unless you're only pfing fights, but literally the only thing that nocturnal astro would have that the current astro does not is a small shield on opposition which has a 60s cooldown and a regen on intersection. What's the point of getting sects back if that's the only difference? Just ask them to bake those into neutral sect and you'd have what you want more or less.
iii) Your stance dance suggestion conveniently gives the good(damage buff) cards to nocturnal and the ones that no one would want to use(random buffs) to diurnal so the only thing it would accomplish for astros healing with a shield healer, would be them having to swap to nocturnal every minute so they can get the cards they actually care about. Astro already has way more than enough free heals and damage reduction, so you cannot possibly tell me anyone would choose to get the free heal/ free dr, especially when you also get a lady card once a minute with the new cards.