The whole rank thing is mostly a tradition game to me. For whatever reason I played the salute side of the game as I mentioned. As to the Sir thing, well I first met one guy as a captain, me an LT. I called him by his first name for a couple years till he made major, suddenly he railed me for not calling him Major XXXX. Another guy I met as a major, but everyone called him by his first name, the same as mine. Obviously two guys named Bob had a running joke that went something like:
Him in a manner of greeting: "Bob"
Me: "Bob"
I got chewed out by a different officer about calling a major Bob, while I was an LT. After the ass chewing, he talked to me and said something to the effect of, don't worry about it, I'm cool with everyone calling me Bob, you guys do what I tell you, jump when I say jump, so what you call me doesn't matter. I learned some important things from all that. Respect someone's leadership position above rank. Know your audience. When you're the higher ranking SOB, don't take shit so damn seriously, Sir/Ma'am doesn't equal respect and if you're a good leader you'll recognize when your people are following versus appeasing you. I also learned through some other interactions that it's a slippery slope. If you get lax with some people who are good shit, it makes the shit heads think they can take the same liberties. Use your relaxation with caution, it may come back to bite you in the ass.