Leveling up doesn't do you a whole lot of good overall, you increase your stats by touching those crystals, and theres a stupidly easy one to get in hythloth that you can get to right from castle britania, that will increase your stats without having to levelup, thus you can fight the unavoidable fights at a lower level, with that in mind, you can avoid leveling up as long as you have the healing spells to balance it out, also purchase a ton of oil, it helps a great deal in combat.