I for one, would love to play the old fragile mage.
As said above, it could definatly help with the archetypes.
Young = Stealthy
Middle Aged = Stronger
Old = "Wiser", and better at magic
Seems great to me. I'd love to walk around with a limp and a cane, only to turn around and fireblast a bandit in the face. False Sense of security. Can't go wrong.