Lol yea I thought about them rolling around in their bags while on land too, pretty funny but realistic concept. But yea, them swimming through the air doesn't bother me either; they're toys. Heck Spidey, Venom, and Quorra swing from the air as well and that doesn't seem to bother anyone.
The riding a wave ala Hiro could be cool too.
By the way, on PS4, does Hiro's wave disappear for anyone else mid-ride? Or just me?