I have 21 units and have recently formed a Series LLC for all 21 units. That has gone smoothly with the exception of one unit that I have my disabled brother living in. I have placed 50% ownership of that one unit in ...

   #4 Is great and I bet this one can lead to many successful closed deals. 

You bet it is lower risk than being on the equity side.

With training, it's great.Time spent varies from Client to Client, but I'd bet they probably spend ~30min answering our questions and clarifying transactions to close out the year.

I bet the rate of Engineers going homeless is all but 0. 

Your best bet is to get the rec from an investor-friendly agent who also flips (but be very careful with this, so many fakers) or an investor.

Relatively low cost means you aren’t betting the farm—really just your down payment.

Wishing - betting death on your tenants?

As a rental, tenants will likely prioritize the location over minor inconveniences.Your strategy of betting on appreciation and eventually pulling equity makes a lot of sense in this market.

Liquidating the property is by far your best bet.