I bet you could make little to no money in 20 hours a week.

Then your best bet are probably community banks which have more flexibility (albeit worse terms) than larger banks and also worth looking into are DSCR lenders.

As I've witnessed, rebranding can make a significant difference in the success of a property, even if the physical appearance remains the same.By charging appropriate fees, exploring additional income sources, and undertaking property rebranding efforts, real estate investors can unlock the full potential of their investments.

You bet.

This is what allows you to do deals without physically going to meet with a seller.

Physically verify everything.

When you have a duplex and tenants on both sides stay for ten years, it almost guarantees that something isn't right.I would study your market and determine the value of your rental, because I bet you are losing money every month.

Tax benefits, use of leverage, and a physical asset that you can see and touch.

I'd bet on Austin over 30 years, but again, not necessarily relative to SFO. 

Your best bet is to keep liquid cash and avoid PMI.