I dont choose the admin's the owner does, I just control the bot. And with about 30+ bans a day, you would lose track of what bans can be cleared and what ones cant. we get about 5000 joins per # everyday....its nice to have a way to make sure the real bad ones dont come back.
And no it dont kick clones, my clone kicker does that =) But once the host is banned the clones cant talk in the # anymore anyway.