Perhaps the world owner could set a series of rules which are displayed on sign up to the world. The owner could only punish people according to these rules. Players can appeal to AM staff if they feel they are ejected without having broken these rules. That way, if a rule states "Players can be thrown out for running the same routes as the world owner", people will just have to accept it. If everyoe clearly has the rules set down before they sign up, they can't complain (well they can, but it would be their own fault...). Naturally, such a system would not allow rules to be changed during game play (but I would expect this).
Any world owners wanting complete control could just write "I can do whatever I want" in the rules (which, it appears to me, is the status quo) - but how many people would join a world knowing that?