So far I’ve been read Ken McElroy’s ABCs of Real Estate Investing and just ordered his Advanced Guide.

Thirty-two doors in two years is a result that cannot be argued with.It would be great to hear more about your process.

I'd argue that you are more likely to see changes to AirBnB - stricter rules, maybe even a tax, or something like that rather than an outright death.The supply will become more and more saturated and profit margins will become slimmer in most areas.

I would also argue it matters how many properties you have, and how complicated your financial situation is. 

Ignoring the resale aspect, I'd also argue that is is easier to manage SFR rather than multi's.  

I've also been told (though not confirmed) that a competent lawyer can argue that your property is not actually a business and hold that the LLC is a sham.As a means of protecting both your personal assets as well as your equity in the rental properties, you may want to set up a separate LLC to serve as the property manager for your properties.

Regardless of the issue/mistake the bank is owed money and the borrower is legally required to resolve to clear/release lien so they can fund and file book and page.I would advise your client to not argue or delay this to avoid interest and additional fee's and figure out a payoff and resolve quickly.

One might argue that the added $20K in purchase price makes up for that. 

Others can chime in and disagree if they wish, but chances are those that will argue will fall into one of those two categories.

The fundamental aspects of real estate investing seemed hard to argue with, but I realized most of the people I was learning from were selling information first and tangible real estate second.