Any insight and help is much appreciated. 

Or be doing 1031 exchanges and go from 4-5 unit properties to 10-15 units, then 15-20 units, then 20-30 units, then 30-40  and so on until I reach 100 or more units.

I would like more insight on this topic also.

My question is: since we are both already on title, which of the following best describes our situation:  (Note: no money is being exchanged and he will not be living in the property) A gift among family members where no money is exchanged A transfer among family members where only nominal consideration is given 

Eide Bailly seems to agree with rents now being subject to SE tax: https://www.eidebailly.com/insights/articles/2017/11/tax-reform-bill-released

In other words could I sell this property after 2 years and avoid cap gains tax without doing a 1031 exchange? 

After my divorce, my standard of living plummeted, but I got something much more valuable in exchange: personal responsibility for my future.

While AirBNB is certainly imperfect about how they handle resolutions, I think there are some valuable insights here about the necessity of documentation.Putting myself in AirBNB's shoes, photos and invoices are absolutely critical to resolving disputes and damage/expense claims - otherwise, they would be at the mercy of people who wanted to abuse the system and make frivolous or false claims.  

Any insight would be appreciated.  

Look into the hold requirement of the 1031 exchange.