Getting to the level where Barbie's at requires serious dedication, it should not be easy to get to such levels. I really don't see the point in having a load of level 600s. And for the ladder to mean anything the levels must mean something.
And well yeah, I suppose AFK leveling on touched ones would be somewhat effective but it doesn't mean it should be removed just cause some people want to cheat their levels. It just means I have to do more macro checks and log on at times when people don't expect me to be on =p
As for the monster levels, are you suggesting they spawn with a certain level? I like the idea of having more variation in a single type of monster (perferably something visible too, like slighty bigger, but that's not going to happen in the current client, but ofcourse, we do have the name changes on monsters as they level). It would, however, require some work on Zer's part, I have no idea how hard it would be to add something like that in the server and contraints of the current client.
@Zer, perhaps 'abuse' the Flags field in spawn editor? (What is that used for anyway =p)