Regarding your credit score drop, the most common thing is for your score to take a hit after a credit inquiry, a new account opened and your average age of accounts reduced. This is temporary, as your score will improve again within the next months if you manage your card responsibly.
I wouldn’t pay too much attention to FAKO scores, your FICO score could’ve dropped only a few points. Monitoring your credit report is what I think is valuable about the services offered by places like Credit Karma and Credit Sesame.
My score dropped after opening my first secured card, but improved after a second one for some reason.
Regarding opting out and removing old addresses, I don’t know much about this topic, though I’m sure this other person is not going to be affected by it. I’ll see what I can find out.