@Eloah,
I was posting the idea as an intellectual exercise, not to get it implemented. That being said, I'm fairly certain they have not said Astrologian is this game's time mage. Time Mage in FF has never been a healer and AST only has 2-3 time-related abilities. As I've mentioned several times in the thread so far, consider Astrologian an astrologer who dabbles in time magic, and a Time Mage a master of time magic itself. As for the name ideas, SE can choose whatever names they like, but I like the names I picked. I picked them for a reason.
To your consistency/explanation idea, I think I've given much more explanation than was necessary. I think Armageddon Counter was explained well in the first post. It builds from 1 to 10 when Prophetic Blow I, II, or III is used. After PB is used, the Armageddon Counter has a chance of activating equal to its level times 10%. If it activates, it resets to 0 then unleashes one PB attack (of the same level that activated it) for each Level the Counter had. So its a massive burst of (low) damage, but when 5, 6, 7, or 10 attacks come at once, it's a very potent burst of damage. So individual attacks of Time Mage are meant to be weakest in DPS, but in short bursts, it'd be the highest.
The MP cost on Abilities was an oversight. Time Mage is meant to primarily help the party and is supposed to have few ways to damage. The rotation for damage is simpler than most other jobs but gets slightly more complex at higher levels. And Time Shield can indeed kill a party member, but that's obviously not the intended use. They are nice uses for Time Shield I and II if you think about it.
And I'm not sure what you mean about the traits. They're pretty basic traits and make the job a lot more usable.
Please feel free to reply.