When it comes to people not being able to separate their characters or judging a character based on the actions of an alt, and similar things, I can safely say that from an AoP perspective those things are very hard to prove. Yes, often it seems _possible_ or even _likely_ that such things are going on, and we all know they are. But do you punish someone based on something you _think_ is going on? There have been many cases when I as AoP, and later AoD felt it's likely shady stuff is going on, but when I was unable to gather clear proof I had to drop it. There's really nothing else we can do, because punishing people based on rumours or what you believe is _likely_ would suck horribly if you were wrong.
But we have taken action against some who have had trouble separating their characters, because sometimes there ARE proof to be found. The last couple of years several people have been caught using a character to benefit another character. Both players and wizards have been caught dong this and been punished for this. It has been first time offenders and fairly "minor crimes" though, so there has been no deletions, but a couple of quite harsh punishments have been dealt out. Like losing all your combat XP with no recovery and/or lengthy suspensions. These cases are easier to prove than stuff the goes on behind the scenes though, or in the case of treating someone differently based on their alt's actions, that kind of takes places inside someone's head, making it extremely hard for us to prove, since not all players are exactly 100% honest.
AoP: "Hey, did you deny X entry into guild Y because you don't like their alt, it sure looks like it?".
Player: "No I didn't, I don't care about that, their application wasn't good enough and i didn't think they knew the guild lore."
AoP: "Mhm... their application looks fine and they're an excellent RP'er."
Player: "Well, that's not what I think, my guild has very high standards."
AoP thinks player is totally lying, but... that's not nearly enough to act on. So... yeah. Then what?
Proof is needed, so if you suspect someone is cheat, if at all possibly try to find proof and send it in when contacting the AoP. Because if it's something I have, unfortunately, learned as AoP and AoD, it is that surprisingly many people have absolutely no problem at all with lying straight to your face in order to save their own butt.
A word of advice though: DON'T DO IT. Because when we actually sit on logs or other proof that you don't know of, that proves that you are lying, the lying will just make things ten times worse for you.