@Jon D. some questions, the answers may help you better focus.1) Why did you pay your primary mortgage off in the first place?

That means paying all cash isn’t an option unless you plan to bring another $600k to the table. . 

Speaking with the seller's agent, all the tenants are current on rents and pay rents on time.

Now, I'm imaging a scenario when every one of these tenants move out that I'll be paying their entire security deposit + interest even if there are damages beyond normal wear and tear. 

I was told by a local experienced investor that insurance companies will always go cheap with paying out to contractors in the event a property needs to be rebuilt. 

However, aside from that, I couldn’t find much information about them, and the only online presence seems to be the wife’s LinkedIn profile (though I’ve never met her in person and am just going off her profile picture on Zillow).After submitting the application through Zillow, we attached our income (two months of pay stubs for each of us from our current jobs), work references, credit and criminal background, rental history, and the contact info for our current landlord (who just so happens to be my fiancé’s father).

To be clear, you are not paying off the 80K mortgage.

How much do they want you to to pay, to pay off one of the mortgages (or both of their existing mortgages)? 

If the new owner pays on the loan its not "equity skimming" from what I understand of it.

The investment in the plane ticket and hotel can pay off huge when you are able to find and focus in on a specific area.