However, the specific details can depend on various factors, including the type of asset, how long it was held, and any applicable tax exemptions.

Unless you have large medical bills it's not going to make sense.

The S election does not exempt you from that.

We've backfilled plenty of pizza huts, boston markets, etc that have single tenant free standing buildings and generally these buildings are highly desirable for other uses as well, we are often shopping for a medical user for instance.2) There is usually another restaurant operator looking to backfill a space and not have the buildout cost associated with a shell space.like with all things in real estate its a spectrum, and what you are looking for in a return, flexibility, and budget will generally narrow what is feasible for you and your search.have you given any thought to the above (ie returns, budgets, other uses)?

Keep renting it out and deal with the tax implications, move back in and aim for that tax break on selling later, or sell and possibly pay capital gains tax if he doesn't meet the criteria for the exemption.

The cost to go up in limit is normally cheap)Medical payments  (for small cost injuries that happen on site. 

I hope to be able to sell this house and retire where I wanted to.I need certain medical care for myself and my son.

It might require a security exemption, however, which is something you should check with your attorney.If legal in your state, you can fractionalize your loans -- also called a multi-beneficiary loan.

I believe the results can be used for up to 4 years, then any non-exempt properties must be re-tested. 

I think even more than medical....if not they are a close second.