Personally as a 60 AST I have had very little issue with MP management - it took a few dungeons to get used to post 50 however it's a simple case of managing your cooldowns/cards effectively.

Aside from possibly a slight potency tweak on the Nocturnal Sect stance, the only changes I would want for Astrologian would be;

Instead of having Shuffle (returning card to deck) would be something like;

Fold - Returns the drawn card to deck with a 50% (possibly too OP at 50%) chance to reset the Draw timer.

As much as I appreciate Astrologian being a RNG job, I think Draw gives more than enough RNG opportunity. Using Shuffle I almost always pull the same card again. You could argue that "Okay you've got Bole again and already have Enhanced Royal Road stored, just use the damn thing and reset the Draw timer damn it" however I'd predict much more effectiveness of being able to return that Bole card and possibly reset the Draw time.

Time Dialation I think is a wonderful skill, however I think it should be possible to use on ourselves. Luminiferous Aether cooldown can be shortened with the Spear card, however 15 more seconds could make all the difference in a healing intensive battle. Especially considering how AST lacks a healing buff such as Divine Seal or Rouse, they would likely need to throw out more heals to keep up. The same could apply to Celestial Opposition also and as well as extending your cards effect on the party, it could also prolong Luminiferous Aether.