It sounds like a very idea,
an intresting one could be adding more affects from Stds, maybe your character would have moments when the screen is blurred, kinda like when they are drunk (but without you gaining the same weight as a small child)
It could add some new difficulties for the player, Get caught in a fire trap?, your skin is burned you loose more health from an attack as a result.
They could also implement (cant believe im saying this) some form of crippled limbs like there was in Fallout 3.
Overall I think that if Lionhead gave us the ability to injure our character severly then it could help us bond with them overall....Or give the trolls an extra thing to complain about >.>
Although it would be nice to see it implemented.
Regards,
Fiach