You're def right that a wrap or AITD can offer more protection to the seller than a subject-to deal, especially in terms of maintaining control over the mortgage.

Having them each inherit a duplex is a powerful way to set them up for financial success while maintaining cash flow for your future retirement.Overall, your plan is ambitious but entirely achievable.

To thrive in real estate investing, you must maintain a firm grip on your finances.

What would be the return if they put it in the stock market, bonds, syndications, real estate notes, etc.

The difficult part isn't finding that property; the difficult part is finding quality roommate tenants and having good systems for screening, setting up rules and maintaining your future investment to achieve the best results. 

I would be happy to discuss some of the processes that I use to find quality tenants who want to live in and maintain a quality home. 

There are also additional costs of operating and maintaining an LLC, like separate bank accounts, annual report filings, tax filings, etc.2.

Is it feasible....if the structural integrity of the house is maintained, are there other issues to consider. 

Sure it can be a write off, but my question is if it is the highest and best use of your time (or the given employees time) to be running a skid steer - transporting it, storage, maintenance, cleaning, etc, and if it still makes sense if you need to hire someone to run it for you and take care of the other things.Add up all those recurring costs - maintaining the machine, maintaining the trailer, having a large enough truck to tow it, insurance and registration for all of the above, your time or your employees time related to all of the above...even at $14k a year it might be attractive enough to keep paying that and having them drop it off at the job site for you.A brand new machine could easily cost you over 6 figures - that's 7 years of rentals at $14k/year before including all the holding costs. 

There are also additional costs of operating and maintaining an LLC, like separate bank accounts, annual report filings, tax filings, etc.2.