Non-Cleric/Wizard Spellcasters

What about making the moves grant you a "caster level" of 1/2 your level, round up, no matter when you took the move?  Scales nicely, protects the niches of the primary spell casters, and avoids the "crap, why didn't I take this at level 2?" problem.  Also, makes the move write-up shorter.

Maybe a second move (for levels 6+) that lets you get caster level = your level-1. Or heck, maybe your level-0; you spent two moves on it.  That'd account for your bards & paladins for whom spellcasting was central.

I dig Jeremy's idea (:

Also, no one ever addressed why Fighters (but not Bards or Paladins) can already automatically jump to LV - 1, even if they get the advance at Level 10. Is this unintentional?

It's unintentional. The Fighter move is Red Book, the others are pre-Red Book.