Well we could change our passwords to the name of the person imitating us, then when the game is over we can just change our password back to the one we had before. So for example if
SPM was imitating me, right before the game I would change my password to "Saucepan Man", then when he dies or the game ends I just change it back. This way we're not giving out anything personal and it's easier for the person imitating us to remember the password.
Personally I think it would be an amazing game.