Here's how I would change/fix the current AST without reverting it back to what it was.

Divination - Cooldown reset upon getting 3 appropriate seals, or just 2 minutes, 3 minutes seems too long for such a small buff.

Celestial Opposition - Reduce cooldown to 60s. The heals aren't strong enough to warrant a 120s cooldown.

Celestial Intersection - Have it apply both buffs, again it's not very strong and won't cause AST to be OP as a healer.

Horoscope - Cause the heal to trigger when the effect wears off, OR have it apply a regen/shield if not used.

Sleeve Draw - Remove the buff and just make it add three charges to draw (as in no timer to use them)