The third method, which requires some time and effort, involves learning how to pull property addresses, names, and numbers.

You could get another loan on a Duplex I have seen it multiple times. 

Interest rates are poised to start coming down and refinancing is how you time real estate.  

Property B,  my co-owner lives there full time while I live in property A (he has no affiliation to property A).My question is, how should I view the monthly payment breakdown of property B (further details below)?

Renovation time 3 months.

The house at that time was probably priced around 1.3 million.

First time working with affordable housing

This helps you assess the buyer's creditworthiness and ability to make timely payments.

So, yeah, I get it, it's been a good setup for both parties.That being said, (and perhaps this is my naivete coming into this new space) the fact that after all this time they decided to outsource the lease renewal negotiations feels like a "them" issue and like a one-off fee.  

Side question: How can you help ensure a good, timely, mistake free lending process?