Levels don't really contribute much in this game. Level 45 is certainly fine, Level 30 or so is possible too. But yeah, it's the jobs you want to get leveled up more than the characters. It also depends on your style of play. In FFV I tend to be a magic whore with my entire party being able to cast every White, Black, Blue, Time and Summon spell in the game. Then they become Mimics so that they can get in lots of spells. I'm not sure how popular that style is but it works well for me.