Some will pay to stay waterfront but there are just as many I’m betting that would opt for slightly less expensive digs in a very popular tourist destination. 

Many of the property owners we work with are out of state owners, feel free to reach out if you would like to talk.

Does anyone know of a rental analysis calculator type of thing that is free?

Feel free to private message me if u have any additional questions. 

Start with BiggerPockets Ultimate Beginners Guide (free).

My parents have seller financed a free and clear property they operated as a fine dining restaurant in late 1990s, then transferred as a neighborhood bar. 

If you want to hear more feel free to dm.

you should get a RMLO or an underwriter to qualify the borrower. if its owner occupied and in florida you also will need to use a third party servicing company to service the loan which will run you around $450/yr. not an accountant but its my understnding unfortunately the interest income is going to be taxed at ordinary income and the principal will reduce the principal. how you offset the losses talk to your CPA.your best bet honestly is to just sell it and bite the bullet. 

Why would a realtor work with a customer for free.

I have had excellent luck with your local NextDoor neighbor marketplace and on FB Marketplace- better luck on Next door (www.nextdoor.com)- it's free to sign up and you can copy/paste from one site to the other and just add pics to each that you have taken and saved.