A lot of what the seller and his "contractor brother" did was what was later described as "prison work." 

Many people have described the process of investing in realestate as being a slow way to build wealth.

I’m sure there were thousands out there that have done what I described above

If they do accept to move out/transfer to B, would a simple letter signed by both parties describing the cash for keys deal suffice? 

@Vijaianand Thirunageswaram Given how you describe the property, then my answer would change to yes. 

Failure to make complete and timely installments will be considered default by the tenant, as described in the lease of 00/00/2020 and Landlord shall retain all rights and remedies prescribed therein." 

@Connor O'Brien The scenario you described is quite unusual for a 203k loan.

I've seen people read over information on disclosures that described a problem plain as day, then come back after closing asking for money/compensation because of the damages. 

I would speak to his employer and get a character/reference check from them and get physical proof of his retirement income but overall I would probably let someone like you're describing move in.

I threw some numbers in a mortgage calculator to just get a sense of how much the gross rental income potential is vs the PITI and here is what I came up with. https://www.mortgagecalculator...I grabbed the taxes and insurance off of what I assume is the Zillow listing based on what you described.