It grows in one location because there's excess moisture allowing the mold to take proliferate.The first step is to figure out the source of moisture.

They can be very loose with their numbers.

take a guess where excess funds go in Oregon.

That seems excessive.

Avoid investing in cities with high operating costs.Pro-business environment: Companies prefer locations where they can operate smoothly without excessive government interference.

You'd have to work pre foreclosures for a year or more to truely understand the craziness of those owners (who are about to loose at auction). 

I sold some properties, paid off those mortgages and took all the excess proceeds and applied it to other mortgages.

These started out at $400-600/yr and I felt I was making more than that in excess rent.  

Some gas services in San Diego are joint services(shared with another property) sometimes as small as 1/2” PE and they have an excess flow valve at the street which will trip if you exceed a certain flow.

Keep in mind that your refi options change dramatically once you do move out because you will loose the option to use a homeowner's refi and the much better rate that provides.