I think SE should give a secondary box in the Character Equip screen for each slot that actually displays, so that you can equip another item (of the same type) in the slot, and get the look of the second item, with the stats of the first...

This would allow players to run around in their starter gear appearance with full DL on, or allow you to actually use those swimsuits in combat without losing a ton of defense!

Perhaps they could let you even keep the Stat Bonuses (not Def/MDef/ATK/BLK,etc) from these pieces of Vanity... although that could then lead to broken things like someone adding AF2+1 boosts to Allagan boosts... but that's about 6 months down the road that that could happen.