Nice to see in this day and age SB.Would take the title with respect on the first tee. After that I'd probably tell you to call me by my first name.
That is what most people do, if they introduce themselves and say "call me X" I wont bother, most of the senior players like being called "sir".
I think once I start to look older maybe they thing it is a bit strange but I am only 26 and I look a lot younger so it isnt so bad,.
I find that a majority of rounds I only call people sir if they are a senior, anyone who isnt mostly only happens when it feels right ie during a rules check or conceeding of putt in matchplay etc, for general chat and banter it is usually first names.
I think matchplay should always be sir, its a time where it is also a mental tool as well as good etiquette.