The complex consists of one 10-unit building, two 2-unit buildings, and two cabins.

Very creative with adding a 1 in there and with a text mail account, they will never answer the phone, which is another reason to be cautious with someone who can only communicate through email.  

I'm seeing relationships and communication be the common denominator here.

It will take consistent action and focused effort. 

WHICH ones do you like, that have communications Built-in, through an APIs, and can track response of marketing outreach programs like text messages?

You will figure out what works best for you and when you do stay consistent with it.

But to someone who has only lived in the suburban McMansion area their whole life, it might be a C/D (there is a bus stop 300 ft away the consistently has someone with a brown bag in hand, people keep their houses nice, but they are mostly 70+ yrs old, cars park on the street because most don't have garages or driveways).I agree with @Erik Whiting, there are people in all income brackets that are good, responsible people.

City Code Enforcement: Properties that are consistently getting warnings and citations for failure to care for their property could easily be rentals where the landlord is over his head and would take an out, if presented, but can't afford to fix up the place to sell it.

They had very little to no communication with us.

Also, I think there are investors you can start to communicate with and potentially invest with on Bigger Pockets.