My suggestion for AST

[Vlady]

Make synastry a "permanent effect" (recast 15-30 seconds) like beacon of ligth from WoW
Reduce celestial oposition to 60 seconds and add some healing potency
Let Colective Unconcious be like other healers barriers
Buff potency for all the cards 5-10% to be relevant
Change party bonus to MIND
Spread out of combat

Synastry is a very unique buff for ff 14 and our best cooldown. It is very potent for sticky tank healing situations even letting astros solo handle tanks in situations that may arise. Bismark EX/A1/A2 are already excellent times that Synastry shines. It does not need a change. Spread is going to be changed with the astro buffs along with shuffle cooldown.

[Nihility]

Synastry is a very unique buff for ff 14 and our best cooldown. It is very potent for sticky tank healing situations even letting astros solo handle tanks in situations that may arise. Bismark EX/A1/A2 are already excellent times that Synastry shines. It does not need a change. Spread is going to be changed with the astro buffs along with shuffle cooldown.

the funny thing is though...
with all of astrologians downfalls compared to other healers changing synastry to have 100% uptime with a cooldown to switch targets would make up for all of it without having to change anything else