Probably the best way to go about it (and the best way to do Red Mages period) is to specialise in Buff/Debuff spells. The magic stats don't really apply for the Buff skill, more the skill level. Plus using them in every battle will soon knock them up. Plus their effects are usually consistent (Aura needs to be higher level to be more effective). Debuffers are a bit iffy, but again it's more the spell level itself. Offensive wise nothing beats a good old melee weapon.