I recommend you focus on meeting that limit right now so you can legally close this tenant's account.

You'll be negative every month.As mentioned above, you can't do a clean seller finance (where you get the title at closing) unless you put down $80k to pay off their existing mortgage.  

Is there anyway possible to verify there were actually other offers especially after closing?

You will lose money to inherent issues that plague lower income populations.

This will be subordinate to the existing FHA loan, but you’ll need to qualify based on your credit score, income, and debt-to-income ratio.Home Equity Line of Credit (HELOC): A HELOC could also be an option, offering flexibility in how you draw and repay funds, though it might come with variable interest rates.Balloon Payment Loan: This type of loan can offer lower initial payments with a large lump sum due at the end of the term.

Everything your want to know is online, but, if you needed $100,000 or more to pay for Down Payment and all the Closing Costs for a Home, would you really want to even start?

They can get blackballed forever from closing FHA.

I am seeking any knowledge and guidance that can help me close my first deal.

If you plan to be there LESS than 7 years, then I might consider NOT BUYING because if prices stay the same it will take nearly that long to pay down a mortgage enough to cover commissions and closing costs to sell and break even. 

You may be able to close and then do the 2nd mortgage afterwards, however.