You comments about being less formal with the people you like, reminded me of a passage from "The Gulag Archipelago" by Solzhenitsyn. In it he stresses that "your friends will argue with you". If he told someone that he was going to do something stupid, like talk back to the guards, his friends were the ones trying to talk him out of it. The guy who was encouraging him, saying "Yea, tell them what you think" might appear to be supportive, but in reality they were definitely NOT his friend.

I've been know to play "devil's advocate" with system designs and some people accuse me of arguing too much. I just tell them about Solzhenitsyn and let them know that I'm "very friendly" Nothing solidifies a design like having to defend it against alternatives.