So if I'm understanding this right, there's no real reason to NOT class change from a Sorcerer to a Sage the second you can. The Sage gets every sorc spell -- and then some.
The only alternate path would be Sorc -> Puppeteer -> Sage, but that's pointless cause Sage gets most of the Puppeteer spells, and Puppeteer is really more for the Magic Wall skill than anything else.
Sound right?
Edit: Also, as an aside, getting REAL tired of my Fairy and Celestian's HP totals. Celestian is a Samurai so is front line, but is a Samurai has low defense, and is a Celestian so has crap HP. My Bahamun has literally 10 times the HP as my Fairy, and despite being in the very FAR back row, she still gets hit often enough to die (in one hit), and trap walls instant kill her if they nail her.