California is probably very different though so I would speak to people in your market about it. 

I know people who've had success with Buildium and I can tell you from personal experience that Appfolio can pretty easily handle a portfolio of several hundred units.

However Property tax's some of the lowest in the coutnry and property maintenance same thing if you buy a stucco home with a tile roof.No real major weather threats like many markets  IE hail storms wind storms etc.. can get windy but thats common.. 

I'm buying the property with cash, in a trendy neighborhood.

No, because they are not a write-off if you're merely buying your own meal. 

Ask questions about what people do, don't talk about yourself.

However, due to very, very high cost of living in Silicon Valley, and difficulty buying a reasonably sized home, and given I will remain in Bay Area long term most likely (family all here), also need a property appreciation strategy to some extent, too.

The problem with these small deals is that there no money in it for the Lender or the investors who buy the payment streams.  

Sometimes people can be misinformed, thinking these are loosely originated mortgage loans akin to the “NINJA” (no income, no job, and no assets) loans that were common in the early 2000s and helped lead to the last real estate crash.After reading this guide, you should be both well-equipped to know what to expect in the DSCR loan underwriting process and be able to dispel any myths about DSCR loans being a repeat of the poorly documented “no doc” loans of the past.

Are you planning to scale and buy more in St Louis?