With weed, you run into issues of medical marijuana and people making claims of medical necessity.

Maybe you're just not ready for this type business or could find a way to figure it out on your own.Alternatively, look at medical doctors.

So the county at some point is likely to take a bigger chunk with the stated purpose of offsetting the increase in emergency medical response. 

A bankruptcy that's not their fault, medical bills, foreclosure all could be reasonable.

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

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)?

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.

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

In a perfect world, your primary would be paid off and the only HELOC on it would be for peronsal emergency issues - job loss, medical, etc.Recommend you find a lender that finances rentals, get a refinance going, then watch mortgage rates for the next dip to lock in a decent rate and close.