My only concern above, and maybe people are over simplifying it.

First off, the housing collapse was (in a simplified manner) 2 MAIN actions: a housing SURPLUS (and a massive one at that) AND a significant monetary contraction.

I personally pool up to 50 SFH per LLC and set up 1 LLC per Commercial property, I also set up 1 LLC in each state I'm doing business in to simplify my accounting. 

I guess when trying to simplify it one could say that the logical deduction from the often voiced mantra "use other's people money" is "hell, even more so use your own money where available!

Some banks offer credit card programs that are designed for multiple LLCs owned by the same holding company, which can simplify the process of managing expenses across multiple accounts.2.

The math is super simplified, so please don’t hang me for that!

On your lease renewal, simplify the arrangement and just add that cost to base rent if desired.It's effectively really similar in structure to most real estate deals... leverage credit to obtain something, and then charge more for it's use than it costs to obtain it, set aside a percentage for repairs and maintenance, and pocket the net.

My grandparents are in their mid 80s, sold their house last year to rent and simplify life.

I will have to see it the current executor would be willing to get the tenants on a lease as that would simplify the process.

Yes this is incredibly simplified, but my opinion is that whenever you limit yourself to one geographic area, your opportunities are severely limited as well.