Since + to be (part1)?

Hi, dear teachers. I did a search on fraze.it and found these sentences.

Could you please tell me if I understand them correctly?

1. As a native whose family history in the city goes back to the 1860s, I am very attached to my hometown. Yet I haven't lived here since Joe Alioto was mayor. I have commuted to work here for 25 years. So I look at the city, in some respects, as an outsider. I see the city in a new light each day from the Golden Gate Bridge. And for the past seven years, I have been one of its most devoted hometown tourists.

I think this sentence means "When Joe Alioto was mayor, I lived here. But I haven't lived here after Joe Alioto resigned as mayor". Am I right?

2. ... be stupid to change something that helps to clear my mind and prepare me for facing the next ball. I have had the same routine since I was a schoolboy, and it has served me well. It was never mentioned before I played Test cricket, but that just shows the different level of exposure...

I think this sentence means "I came to have the same routine the moment I became a schoolboy. I still have this routine after I stopped being a schoolboy". Am I right?

3. It is quite possible that these rules have changed since I was an altar boy. If so, then something is terribly wrong, because I was taught quite explicitly that all the rules of the Catholic Church were handed down by God via The Pope. If they’ve been running around changing the rules, then that can only mean that that Anti Christ has arrived and has taken over the Vatican. Expect property values in Rome to drop. Or perhaps go up. We shall see.

I think this sentence means "The rules have changed after I stopped being an alter boy". Am I right?

4. Du Sautoy, an opera fan since childhood, is hoping to rekindle his musical ability. "If Jimmy Savile was still here, this would be my Jim'll Fix it. I play the trumpet but I haven't played in an orchestra since I was a student. But just the thought of making music again is exciting for me," he said.

I think this sentence means "I used to play in an orchestra when I was a student. But I haven't played in an orchestra after I stopped being a student." Am I right?

Thank you very much.