I think it might be an interesting idea to give negative traits to heros that fall in a battle to represent injuries. They could be temporary but it would help prevent people from trying to push ahead to fast in the game. Plus it add more character to the characters. Bum leg, or patchy eye or....
Considering that characters might die 3-4 times even in successfull adventure, it might get very frustrating very fast. But there might be some merit in the idea, as long as it doesn't go overboard.
As a part of the campaign, definitely not. But as an interesting challenge or difficulty setting - sure!
I would set it up within a each senerio (single adventure) not in the whole campaign. It would make adventures more epic and add some more abilities to make different interesting adventures. Drag you injured companions to safety and all that.
