should i even level ast?

[Averax]

It's actually one of the busiest healing jobs to play optimally at endgame.

WHM just spams glare most of the time.
Scholar is the same with broil.

AST, you're spaming malefic, but the cast time for malefic is such that you can weave in OGCDs no problem, which is a lot of what you're doing with the cards.

Personaly i just recommend leveling up another healer along with AST, gearing up with that healer, and then switching to AST once you've got a comfortable amount of healing gear. Low ilvl AST is rough. WHM and SCH have a much better time doing dungeons at lower ilvls in my experience.