[David Bofinger]

Perhaps the Fresh Air &c enchantments should be implemented more as shapeshifting spells: they long term switch you between an air breathing form with legs and a water breathing form with a tail. Flight could work the same way, giving you the ability to fly but taking away your ability to pick up objects with your hands. There could also be a man-to-horse shift (extra MA, lose manipulative appendages and maybe the ability to talk). More powerful spells might let you adopt hexapodal forms (angel, dragon) which have the best of both worlds.