Regarding crafting I am seriously considering to first level up my weaver and goldsmith to level 50 (but I am Black Mage 36 already), or at least to keep them 5 levels ahead of the regular classes. You can still make gears for 5 additional levels but forget about crafting HQ items. Otherwise they are practically useless. It spoils a bit the main story but it feels rewarding once you get a grasp of it.