When I talk about wanting AST to be redesigned for players who do not like DPS on healers, I'm not suggesting leave it in a state where you still stand there and mash Malefic for the majority content, but to create a gameplay loop that disguises their personal DPS as support. I'll share the sparknotes of the theorycraft I've danced around and made adjustments to here and there in the past:
Some amount of AST's card related actions are moved to the GCD. Drawing and playing cards has the added consequence of summoning a "Lodestar" that visibly orbits around you. Cards played do not immediately provide buff effects, but are added to your current hand. And you'd have another GCD (A repurposed Celestial Opposition as well as another that activate different types of cards), that consumes the cards in your hand to officially grant their effects when you want them. Meanwhile, you have an ability similar to Closed Position or Kardia that you can place on someone else or yourself (A reworked Synastry basically). Whenever the target of this ability uses a spell or weaponskill on an enemy, one of your Lodestars automatically blows up on the first target that player struck, dealing DPS neutral AoE damage.
Simply put, AST spends it's GCDs building and detonating a buff engine that they work on building and rebuilding over and over while passively generating DPS for someone else to execute for them. In solo content, you can give yourself the Synastry buff and bounce between building a buff engine, powering yourself up, and detonating those Lodestars you generated while building your engine with your small attack spell library. It'd feel very bursty when playing alone. At the same time, the other 3 healers would be given more modest DPS tools and would feel reflective of the tanks, where White Mage might feel something between Paladin and Warrior, Scholar might feel something like Dark Knight, and Sage might feel something like Gunbreaker. Astro players would not attack very much at all in group content, but would still be outputting DPS, just indirectly.