My wife and I became "landlords by accident" last month, and fortunately the house has decent cash flow.

Tim, it just occurred to me that you should reach out to @Erik Nowacki or perhaps he could chime in on this discussion.

The asinine part here is that this was a re-sign so no actual build-out occurred.  

These aren't likely events (low probability) but are very high impact if/when they do occur. 

I believe the author died last year in a car accident or something.

An LLC should provide a measure of protection for your other investments or personal assets...from liability that occurs related to assets held by the LLC.  

It is not understood how these booming markets of today would perform in the event of another recession, so they could be vulnerable to massive job loss and/or plunging property values if another economic decline were to occur.

The hold an IRA much like a conventional brokerage would, but have the staff training and paperwork to document the more individualized types of transactions that occur in non-traditional assets such as real estate, notes, private stock, etc.With a custodian held IRA, they are the processing layer.  

That may occur, but with no way of knowing how this ultimately turns out (like most of life), you set yourself up for letdown.  

I found the self-directed IRA concept by accident.