I think the whole gametype of stupidly earning skill levels is bad in the long run. If we cannot make a game that does not need that, we should at least have a server where there are no restrictions at all -- my point is: no script can be as clever as a real player. So what? If a script can pose a challenge to real players, then all the better! (but, of course, I understand the argument about responding and talking real players... difficult problem, indeed, maybe there should be areas with scripting enabled and some without -- it is all about choice -- and if you allow scripting in a controlled fashion, less will try to circumvent that in uncontrolled ways).
Hell, I just had a great idea: why not introduce UNPCs? (user-NPCs) Maybe whenever a user activates a script, his character is displayed as an UNPC -- just like we can detect NPCs from regular players now. That would solve that problem -- und players could also help to create quests and to create great automatized game content (good NPCs which even walk around and adjust to situation -- liike merchants traveling around and which dynamically adjust their prices)!!
Apart from that, think of a combination of a strategy and a 3d egoshooter game. Think of cities fighting each other. Or think of levels in PlaneShift where you can openly attack each other. Maybe don't even tell the players to fight against each other. Let them group on their own will. If they plan to start a fight, they'll have to secure resources (mines) and and and...