IMO just clean it and give the tenant their deposit back (assuming everything else was fine) 1) The owner knows.2) Show the bill for repair3) It's a business, not a charity.

They are going to scream bloody murder... you'll need to ask them to leave 'in order to make long overdue improvements' to the place.If you slip, ask yourself if you started into the RE business to make money or to be a charity.

Once you apprentice in these occupations and become that top tier your business activities income will give you the means to do what your talking about  travel the world  buy a sail boat  buy an airplane take tons of time with family ( for me start a charity )  or just hang out on BP LOL.    

So get a Heloc on your rental and put the entire rent to the Heloc while still maintaining some liquidity.There are multiple threads over several years debating this subject.Donate the $1000 to a charity of your choice.

, setting up an FLP, or turning it into a charity, but most of that would require planning well ahead of the sale (or concurrence from the buyer).

Is this an investment or a charity?

You're running a business, not a charity. 

I'd think about it like this: 1) I agree that it seems hard to fathom a situation where you don't split out the land and parcel as a separate enterprise.2) It doesn't sound like this is a charity case for you, it sounds like a business deal.

You could just as easily donate whatever you feel is excess profit to a charity of your choice. 

While we all can feel for an older person on a fixed income, you are running a business here, not a charity.....If you really want to help, you can research and help her with housing options for low-income elderly.