BIG BAD WOLF: I like that idea, i put that in my Brainking DB post. There has to be a time limit somewhere before they are removed or retired. I could not possibly challenge on all the Stairs i am in, although i do try to keep up.
I think that Brainking should still run a script once a week to see what ones you are open for a challenge on. Sometimes i finish a game & go to the Stair in question and there is no one to challenge, but who is to say 2 hours later there wont be ?
To save having to check all the time we could have a message sent to us listing what Stairs we can make/except a challenge on.