Yeah, Freelancer-only sounds like it would be an incredibly boring game. I actually started a challenge close to what Seath described though, not too long ago. Basically, only two job changes allowed for each character over the course of the entire game. So if I want to have a black mage with white magic towards the end of the game, I would have to change to white mage as i get that, and then not touch it until I had white magic maxed (or at whichever level I felt was sufficient), for then to level black mage.

I don't think I've experienced any of the issues you seem to have with job systems.