I feel you OP. I wish I could de-level all the jobs I was forced to level for Cross Class and level 30 Job promotions. I never ever see myself playing DRG, PLD, or MNK but im stuck with them. I tried to play them just to manage my neuroses that they were unlocked on my profile but I just don't like them.

The best thing I can suggest is level it to 60 and never ever touch it again. That way its a clean number at least I ended up doing this with all the jobs I don't like playing but was forced to unlock to get things like B4B or Provoke in 2.0 - 3.0.