(They have the deferred maintenance you'd expect after a fixed income senior lived in them for several years, plus smokers, pets)So how do I turn 5 straggling houses into a proper real estate portfolio and well-managed rental business? 

The specific location ( 4' * 6' long) is underneath a guest bedroom window in the front of the house. 

Currently listed 2 houses 1.5m each and the market is dead.

I would learn all you can, go to meetups, build relationships, but only buy something now if you are going to house hack it for the two years until you go and then just rent out your unit when you go.

Purchase price: $295,000 Cash invested: $22,000 Before moving into this house we had to add piers under the hours as the previous were not grounded with cement.

Assuming I spent the last 15 years investing in Ohio, the investment return would be significantly lower.I will continue to invest in SF Bay Area, not in the city of SF or Oakland though.

@Agustin Silveyra have you looked into finding a house hacking agent yet to guide you?

My houses are usually in the $200K-$250K range

It would be even better if you can get something that you can easily house-hack like a SFH w/ an efficiency attached to help out with the mortgage.

Only bad tenants live in bad neighborhoods no matter how nice the house.