Plus there is a timestamp by a 3rd party. 

You have to decide if you want to accept their terms or not.In my town, a HELOC is usually based on an appraisal that is done by a 3rd party, not a county assessor.  

That part is going well!

But for the most part I think you'll just have to treat the majority of the expenses as an improvement.Most CPAs don't charge too too much for a consultation.

For me the issues would be: 1) AirBnB might cease to exist.2) AirBnB might cease to be legal where you are.3) AirBnB involves having dozens of tenant relationships per month, instead of one every year or so.4) There have been some horror stories about people AirBnB'ing houses just to throw massive destructive parties. 

You can dictate your terms   and its up-to both parties to pick and choose or reject the terms and conditions.  

(d) The provisions of this section may not be waived or modified by agreement of the parties. (2005-423, s. 7.)https://www.ncleg.net/EnactedLegislation/Statutes/HTML/ByChapter/Chapter_42.html

We quickly got in touch with the listing broker and secured the deal before too many parties became involved.

Perhaps a nice 1950's built bungalow.Always hire a 3rd party property inspector to give you an unbiased feel for the home.

@Davey Seidenfeld Late to the party here, but I'm an agent here in South Jersey focusing on investors.