(My plan is to consolidate that debt and pay off loc within 18 months, then potentially use it as down payment on another building)I’m feeling a little stuck and looking for some advice.

Check with your trusted local licensed electrician.

Would AirBNB still recognize me as the property owner and the one collecting the payments once they generate tax documents? 

I lived in Saint Louis for most of my 20s (and grew up in the general area), but even after being gone for over 10 years, I wouldn't trust my ability to pick locations outside of the no brainer A-B areas.I hit my FI number and have left my "golden cuffs"; I don't know your situation, but I what I can probably promise you is that it is going to take longer and be more difficult than you expect. 

Despite my concerns, I was convinced to proceed with the promise of a more manageable payment plan and reassurances of quick success in the real estate market.

That's the correct answer, commercial mortgages are a lot more flexible about down payment sources, etc, than home loans, but pragmatically (loan requirements aside) you need to bring SOMETHING to the table for anyone to want to bring what THEY have (down payment etc) to the table.

I was told an initial one time payment plus $500/month.

Your #4: 97% of my customers are return customers and are happy with and trust my service and abilities.I do not have rich friends or family. 

Investment/conventional Mortgage with a cash down payment How did you add value to the deal?

Think of it as making new friends with benefits – of the real estate variety.Leverage Your Cash: Use your cash for down payments and renovation costs.