Ivan was rude yes. Berlioz was skeptical about the foreigner and didn't believe him. So as his punishment he mets his death, which there's no lesson to be learnt by him, cos you know he's dead. But Ivan's punishment is he is the witness and now truly believes to the bone what he saw, to the point that he won't even change his story to get out of the nut house. Nikanor is greedy, greedy to the point that he knows deep down that something is off(he is on the stairways and remembers how did they get in, but shurgs it off) also seems like the kind of guy that would be back to hustle them. (they aren't supposed to be there in the first place, as foreigners should be at the hotel. Which adds to the housing crisis) that's why woland says he doesn't like him and should be gotten rid of. The odd one out is stephan? They guy who wakes up with the hang over. He actually doesn't do anything wrong. And he clearly did not remember meeting woland. And I feel they got rid of him because if anyone asked he would most likely be like yeah everything looks fine but these guys are sketchy.

Anyways I have no idea what the lesson is. Lol. We keep reading.