Also look at the area as well in terms of how attractive it will be for people to rent out your units. 

It's not easy, but all successful agents operate like a business with daily tasks to attract leads and follow through on those leads.

They usually sell for a really attractive price because investment property financing is (obviously) difficult, somewhat limiting the buyer pool to owner-operator small business owners (who in turn are typically great clients, as well).  

I'm just hoping someone with actual knowledge of it can provide some information that offers an alternate explanation.

There's very little way to go wrong here since the alternative is paying to live somewhere else anyway. 

Alternatively, we can get a 15 year fixed at 5.25% with $8,800 closing costs.

But Incase they deny it or find other excuse to stall what would be alternatives?

Being listed on multiple OTA allows users that use alternate OTAs to see your STR and could provide a higher ADR even if you end up lower ranked of the OTAs.Basically it comes down to having all your eggs in a single basket and is too risky for my liking.i am one of those STR owners that corrects anyone that refers to my STR or STR business as an AirBnB.  

If you're subject to the Alternative Minimum Tax (AMT), these deductions may be limited.

Are you attractive tenants that meet your screening criteria readily and keeping them as long as you budget for (vacancy rate)?