First of all, it was an absolute stroke of genius to use a job system in an MMO. In almost every way, it is superior to or as good as the one-class-per-character approach. However, there’s one way in which it is inferior that involves items. In order to be as good as a one-class-per-character system, having the best equipment for one job must not interfere with having the best equipment for another job. However, the final rewards for many missions are mutually exclusive. In order to get a different reward, a character must drop the current reward and repeat a battle, and there’s a limit as to how often a character can do this. Perhaps some of this equipment has been entirely replaced by newer content, but some of it has not, and this may apply to future items.
Simply allowing a character to have all of the rewards for each mission is not a good solution, because it would deny the designers the ability to create powerful rewards that would be too powerful if someone could equip more than one reward from the same mission at the same time. However, there’s a simple solution. If a character has an emperor band and tries to get an empress band, the NPC will refuse. It knows those items are mutually exclusive. The designers could create an NPC to store mission rewards or use a current storage NPC. It would be smart about when to allow a character to take something out of storage. For example, a character would have to store a hollow earring before being allowed to take back an ethereal earring.