I like the idea of your card system as it would give back the diversity it had before Shadowbringers. I personally don't know about Lady and Lord of Crowns. I personally rarely used the Lady of Crowns heal.

Just what AST really needs is an ability that restores your mana, like SCH or WHM. Reducing MP is nice and all, but it wouldn't be needed if we could have an ability that restores mana. Since I personally still feel like Collective Unconscious isn't that good from what I've seen, maybe it could be used to restore mana, so basically be another Assize, but it's better than nothing IMO.