Of course don't go there just looking for business, you go because you believe in whatever the group is doing. 

It gives you the flexibility kind of like a credit card that allows you to borrow a certain limit and withdraw funds as needed.

Of course, that's only when you truly cannot find the owner.

I think they used to go up to like 80-85% CLTV depending on credit score.

Painting, for instance- an amatuer could take their time and paint a house over the course of a couple weeks and do a great job, but a professional crew could do the entire job in a day. 

Do not overly complicate the letter, or you will scare sellers and tenants.I want the tenant to sign, of course.

Of course you don't want to over pay for land, but site conditions and construction type will dictate costs....is there underpinning?

Avoid PMI and then go to a local credit union and get a heloc after closing to gift the money back.Have this as a tool in your tool belt but pursue use of the 3.5% FHA, knowing that you will be at a competitive disadvantage if you are competing with non FHA buyers, then you can call in the favor from your gift person.Just know that if someone gifts you down payment money, your bank will require them to sign a letter stating that it is in fact a gift that doesn’t need to be paid back.

I have the credit, experience and the knowledge on how to underwrite the deal to show their ROI in this arrangement vs a traditional sale. 

This is much lower than the costs associated with refinancing.Benefits of Mortgage RecastingLower Monthly Payments: The most immediate benefit is a reduced monthly payment, which can free up cash for other financial goals.Save on Interest: By reducing your principal balance, you’ll pay less interest over the life of the loan, potentially saving thousands of dollars.No Credit Check or Appraisal: Unlike refinancing, recasting doesn’t require a credit check, income verification, or home appraisal, making it a quicker and simpler process.Keep Your Current Interest Rate: If you have a favorable interest rate on your current loan, recasting allows you to maintain it while still lowering your payments.Drawbacks of Mortgage RecastingRequires a Lump Sum: Not everyone has the cash on hand to make a significant lump sum payment, which can make recasting inaccessible for some homeowners.Doesn’t Shorten Loan Term: While your monthly payments are lower, recasting doesn’t reduce the length of your loan.