I don't think you need to even probably get in that many houses to know your numbers. 

I also called a house that's in my neighborhood with a for sale sign, didn't pick up the first time around noon, and I shoot her a text, didn't response.

No different than all the RE agents who put "great cashflowing property" describing a $500k house that rents for $2500 a month. 

"letters")  as you have pictured it,  why would anyone believe you can buy their house in cash when you can't even afford a damn printer to at least TRY to come over as financially stable credible and legitimate.Yeah right?

Hi -- I'm working on a house that will be in a lower-income rental area.

Anyone else here use them, they are all section 8 housing.  

For example: I live in the first house for 2 years from 2020-2022.

Any business where you're going to be seeing more houses than a normal person sees is going to help you add value in a real estate transaction.

Should we sell these condos for better cash flow houses or try to find owner financed deals?

I have asked my tenants to confirm their contact info and names of all people living in the house including name and age of their children.