I've crafted terms that are a win for me and for my buyer, but my intention is to hold the deed of the property until the buyers's note to me is paid in full, exactly as the banks do.   

There are lots of flaws with the argument though:1.By nature STRs do not have long term contracts with their "tenants".2.  

BUT this applies to experienced builders who have a strong track record of successful projects without trailing loss history.  

A house hack is a solid way to get started as long as it aligns with your long term goals.I agree with @Samuel Diouf and @Jackson Ebersole's comments.You'll want to consider the competitiveness on Long Island.

Are there any terms we should add to the transaction language to protect ourselves from the seller backing out of the contract?

After scouring the market, I was able to get large builder financing and discount incentives that allowed me to buy the property at below retail price and get good financing terms.

I didn't see a specific subscription for the BiggerStays newsletter, but selected the Short Term Rental newsletter. 

I'm looking forward to getting to know you, learning from you, and hopefully soon sharing my own knowledge -- and success stories!

Has anyone had any issues or even success with Bryce Bush who has a Facebook group for private and hard money lending with over 65,000 members.

So I'll tell you now in case there's still time to do something about it:The problem I still have, that I can't solve (but maybe you still have time), has to do with the HVAC system.When you have a single house, and you're renting out the basement, you are asking the house to do what it is typically not designed to do in terms of the HVAC:  1.