Save the Levels for major Stat boosting.
Also note that you only need to boost MP+50% at LV46-50, and HP+50% at LV69-71; the other Levels can be freely used for optional boosting.

These are my recommendations:

Vigour: 128 (fighters)
Speed: 50
Stamina: 42
Mgc. Pwr: 128+ (magicians)