Or did the buyers authorize Escrow to pre release to the builder ????

I would say you need to play to your strengths, whatever those might be.

We cannot breach our guests' trust by playing games with them. 

Signing the lease demonstrates they agree to the terms and then you can hold them accountable.If you don't do this, then the person named on the lease and paying the rent could disappear and you would have no legal authority to charge the remaining three for unpaid rent.

BTW, I am not disputing you, just playing devil's advocate and wanting someone to challenge my thinking. 

The tourism authority has had some good information in the past about how many visitors come to each island and, of those visitors, how many book STRs.

membership is something like APPL which is just non regulated group of private investors working on best practices but there is no authority behind them like  state license or NMLS registration has ..

Quote from @George Skidis: Not an attorney and don't play one on television.

He had other projects that he committed to.Want to play a challenging game?

.- Ask the attorney if your aunt & dad need to authorize lien, or just aunt.2) Understanding your options to force payoff of the lien.- Ask attorney how you can enforce collecting on the lien when you need to.3) Getting full control of the property, while allowing your aunt to keep her ownership.- Have attorney draw up a contract to do this.Suggest you offer your dad some cash, now or in the near future, to motivate him to transfer his ownership to you.It may not work out, but you will learn a lot either way!