Cut to about a year later, my brother buys a home for his family and the big-time real estate investor plan sort of fell onto the back burner.

I recently received a judgment against a tenant who fell nearly $10K in debt to me.

SF proper had very few foreclosure, and the core of the city only fell 15-20%.

I had a nicer house under contract but the deal fell apart.  

You're likely going to a bigger bank (I had this same issue with "fells wargo"), I simply found another mortgage lender that would do it.

That is, if they haven't recently done a BPO for a previous contract that fell through.

As I began evaluating housing options for when my lease ends in August, I slowly fell into an internet rabbit hole that took me from looking at renting a single room, to buying a house and renting the spare room(s), to debating a live-in duplex/triplex investment, all in the name of getting my monthly housing expenses down (and maybe even turned into a monthly housing income?).

I didn't have any existing plans to rent it out before they just kind of fell into my lap, and at the time we thought it was kind of the perfect timeframe for both of us.  

Depends on where he fell short.  

I would say most have war stories.... my worst one is a bus fell onto the roof of the mountain rental 2 days before closing (yep!