We would like to sell them and use a 1031 exchange to purchase a larger tract of land that we expect to close on before the end of the year.   

Luckily these two individuals, separate states and realtor companies, had everything working and running smoothly including my title and exchange company.

If you do exchange messages with the tenant there may also be other documentation to back this up for example a message from your tenant saying something like "Since I'm the only tenant its a little harder now, but I will have the rest of the rent on Friday".

He could do an exchange in to a NNN lease, but if that’s not his field of expertise expect a lower income with his deuces work.

My father would be willing to help us out in basically any way that he could, in exchange for modest monthly payments going forward, and is content limiting his capital gains exposure with the owner financing. 

But a lender will only go so far on the risk spectrum in exchange for a 4% to 6% return.  

-AlexYou’ll be able to qualify for the tax deduction and the Like-Kind Exchange based on how you structure the deal, but yes to both possibilities  

After operating the STR for the first year can we turn the STR into our primary residence for 2 years then sell and avoid capital gains tax and depreciation recapture instead of doing a 1031 exchange?

Security deposit amountYou can find plenty of examples by searching for "tenant estoppel certificate doc" or exchanging "doc" with "pdf" for more options.Here is an example and explanation: Sample EstoppelSome have a lot of legal jargon but this document does not need to be so detailed.

While you may get a 199A deduction, you are paying a high tax rate.If we are talking about REIT's listed on an exchange, there are additional overhead costs as you mentioned - You have to get audited financial statements and also comply with certain SEC laws.