These are some good ideas, also how about when a retainer is not in the wards you could send them gathering for example, and thier level directly influances what they can get, I know STO has missions you can send your crew on and if they succeed you get energy credits/dilithium/exp etc etc, a similar system could work well in FFXIV with retainers, or possibly when you get GC ranks you could be given some recruits to do a mission for you and in a few hours they go back to your GC HQ and you speak to an npc and get any rewards.