Can blue Mage burn all the way to 99 then start collecting spells? Or will some spell won't be learn at end game level?
The higher your blue magic skill, the better your chances of learning are.
I burned to 99 and capped skill using Foot Kick and Sprout Smack, as I think I had maybe five other spells at that point.
I then started hunting (and am still not finished).
The only problem I foresee is getting spells off mobs that are pretty weak, but usually higher level counterparts can teach them as well.
I will never, ever set Sprout Smack or Foot Kick again.