I could charge an additional fee to have access to it, and have them sign some sort of waiver indicating they accept all risk and won't sue me if they hurt themselves.

You will need a real estate attorney who does this sort of work, your CPA needs to be involved and it sounds like a lender.

The poison dehydrates the bodies eliminating any smell.

You can take Real Estate as far as your body will allow.

I haven't done so yet, so I don't know what sort of credit limits I can get.

Sort of.When a lender agrees to a DIL, they will own the property subject to all other loans, liens, possible lawsuits, and taxes due.

I have used hard money as a sort of bridge to longer financing, for example to fix a place up and stabilize it then move to a 30 year fixed product, whether that be conventional or DSCR.I do not think hard money is a good long term option as it is expensive, and STR's are long term investments in my eyes.

Some jurisdictions, like I think Miami, makes the homeowner take an assessment of some sort, but I don't think that's common. 

Don't worry tho, our buddy Trump will sort that out for all foreign investors hahaha :) 

You could also get a wire mesh of some sort (this Hog-wire looks good) and have an easy solution to your problems.https://www.homedepot.com/p/36-in-x-96-in-Wild-Hog-Black-Met...