However even the most recent time when Artagel was general I joined, worked toward my promotion that can be done through an NPC/guild setup system. Then for the next two weeks I worked my ass off, spent much time conquering areas as I'm sure Earth can attest to as well as attempting to protect them (silly bastard

And yes I went up to General but I personally plan on holding on to Artagel's principles of it. People won't get promotions unless they deserve it.
I think that if a situation arose where penalties were given for leaving guilds even for someone who wants to uphold guild policies it would be hard to have a guild leader or council mete out punishments. I mean even someone level-headed who keeps characters seperate is still going to feel bad taking a ton of their friends xp at some point and are not going to want to do it.
It would have to be based on the honour system and how much IRL does the honour system hold up. It more than certainly would not hold up in game.