The best rework they could give the card system would be to bring back the variety of buffs -- substituting something else for spire -- and restore the AST's abilities to extend buffs via Time Dilation and Celestial Opposition (and restore CO's stun, which should have never been removed anyway). That might not completely balance the job as far as DPS goes versus other heal jobs, but it would return some of the FUN and identity of the astrologian, which took a woodshed beating with 5.0.