Here's the Astro that I would want personally. The goal would be to rework minor arcana into your "RNG non damage buff cards" While keeping the damage buff cards but changing some to crit chance ect. (I would like more interesting damage buffs like Haste but with how the game works currently that isn't possible).

Draw CD: 30 (2 Stacks)
Note: if card is used on the "wrong target" the effect(s) will be halved like current, Also "%" should be adjusted if too weak/strong, they should roughly be around each other.
The Balance - 6% Damage to target if Melee/Tank | The Arrow 10% Crit buff to target if Melee/Tank | The Spear 18% DH buff to target if Melee/Tank
The Spire - 6% Damage to target if Ranged/Healer | The Bole 10% Crit buff to target if Ranged/Healer | The Ewer 18% DH buff to target if Ranged/Healer

Minor Arcana (Reworked) CD: 30s (2 Stacks)
Minor Arcana now act as separate "non damage buff" cards for utility.
Examples of Minor arcana cards would be, Regen/healing, Mitigation, barrier, movement speed. (more possible that i can't think of)

Royal Road CD: 90s
Changes the effect of your current drawn Minor Arcana card to be a AOE effect.

Added actions: Play Arcana, Royal Road
Removed actions: Astrodyne, Synastry, Undraw, Celestial Intersection.

How to improve healing?
1. Reduce tanks baseline defensive value, this doesn't mean remove Mitigation tools, just remove how much damage they can withstand in baseline, also up auto attacks.
2. No AOE, Per enemy hit healing on tanks (looking at you warrior).
3. Add more AOE Damage, even sometimes having aoe autos or debuffs that will require more healing resources

This also has to bonus of making utility from non healers more impactful but doesn't overwrite the healers job.