Personally I think we can just leave well enough alone. It seems like every time something happens that someone objects to here on PM, there's a meditation saying "we need to limit X", or "why does Y keep happening?". We need to remember that this is an online community and not an online utopia. Things will happen here that bother some people and affect the "purity" of the site. Tough. It happens in real life every day, but we deal with it.
I will agree that being able to remove stale nicks and "retiring" oneself are good ideas, but cancelling someone's account is too much. Why can't there just be some functionality that allows a user to change his/her nick? That's much simpler than cancelling accounts and creating new ones until the powers that be say a person's nick is "allowable". (I won't even get into the heartache I get when I think of having to have someone approve my nick.)
GuildensternNegaterd character class uber alles!