"You don't salute the person, you salute the rank": Do you believe in this age old saying?

Yes. But the ones I didn't care for knew it as I would only use their rank. If I didn't respect the individual I never called them sir or ma'am, same for ones I didn't know. Had that discussion with a lieutenant at Benning, at the BX, when he lost his lid when I saluted him and said "good morning, lieutenant". He told me the proper greeting was the greeting of the day followed by sir. I told him the proper greeting was the greeting of the day followed by rank.

Sir is a sign of respect. If I don't know someone how can I respect them? Not calling someone "sir" isn't disrespectful, neither is using their rank.

I believe you're acknowledging each other as brothers-in-arms. People forget that both service members are being saluted. The custom is the junior initiates the salute and the senior returns it.

Yes except MOH recipients. Then you always salute the man as well as the medal!