The concerned neighbor requested us to do something to put an end to the endless stream of unsavory people coming and going from that rental, with the main tenant in the middle of all of it.

It's essential to educate yourself in property management and tenant relations so it would be a smooth stream.

Will you provide cable/satellite or make people stream?

This can be a very expensive mistake if you don't make the phone call to check.I am not going to choose sides or define multi-family because the original post didn't ask that and also because the answer will vary from one town to the next.I encourage any current or future readers of this stream to look at the original post then follow the advice I have given and will repeat one more time - if you don't know 100% for sure if your intended use is allowed whether by change in use or grandfather status, then call the LOCAL code enforcement office, explain to them your specific situation as well as your intended use, and let THEM advise you.Disclaimer - this is not to be considered legal advice, but I am beating my head against the wall explaining it because it is an elementary lesson in real estate.Best of luck to all.

Would the goal after I get a duplex to use the income streams and my work income to pay it off as soon as possible?

I'm gonna make some money with a local or web business and wait until we get some blood in the water in the housing market.

California though is so expensive that I want to try to create more streams of income with more properties.

My plan is to self-manage so that I can maximize profits, continue to invest in others and build as many passive income streams as possible.

There are online communities and local groups where you might find like-minded people facing similar challenges.Exploring additional income streams that align with your skills and interests could also be beneficial.

Once you have more than enough income stream from the US, taking some riskier gambles abroad may make sense.