I'm talking to a professional poker player from Los Angeles that wants to invest - the advantage to him is he does NONE of the work.

Being in Los Angeles this is a niche locating a VAC rental will be very valuable in our portfolio.

How does this list that includes Los Angeles as a top 100 cash flow market narrow down my focus?  

I'm going to say 95% are not what you may be looking for, especially with a single home.I did this myself, from Los Angeles, with the first 4 properties i purchased out there in Akron, and i still manage them by myself to this day a few years later.

Can you make a safe assumption that in 30 years the Bay Area, Los Angeles, Manhattan, San Diego, etc. will all increase in value an appreciate?  

I would be investing long distance as I live in Los Angeles.

I live in Los Angeles, which is just as insane.

I was driving around Los Angeles early one relatively cold December morning a few years ago, and there were a bunch of Central American guys bundled up about to start some construction work.  

That is why I reached out to her through BP and met with her when I was in Los Angeles - again - several years ago.  

Same for Los Angeles.