Is there any document within the BP website?

Hopefully, you've approved a bid they submitted, so the cost is fixed - unless they can document the need for acceptable change orders.If they are charging hourly, then, yes, they may be able to charge you more the longer it takes.Keep in mind, your PMC is unlikely to have an exterminator and other licensed contractors on staff.

I would not pay 80% upfront, you can go along and make a payment plan while construction is under way, and the result should be mostly the same for the developer, and you don't risk so much before even constructions starts.Have a lawyer go over legal documents so that you know the property belongs to them or if they have it in a trust.

If the amount is significant I draw up a document stating the interest rate and the payment plan.

Document successes to build credibility with lenders for future scaling.

Again, have to be self employed to do this AND rates are higher on these loans.You will be able to add back your paper losses on your rental business by your lender using this form (if they are competent which not all when it comes to investment real estate) :  https://content.enactmi.com/documents/calculators/Form1038.C... 

Obviously, I am going to be very, very diligent about getting all the documents necessary and looking over the area as we get farther into the process. 

This is not the place to cheap out over a few hundred dollars.Lots of lenders and virtually all borrowers never read their loan documents.

Banks like to match short term assets with short term liabilities, and vice versa.I don't believe that DSCR loans are "expensive", but they do require a more thorough underwriting and higher amount of financial documentation other private and hard money loans.It generally helps to have a Fractional CFO or Loan Consultant (not a broker) that will work on your behalf to negotiate better DSCR terms and rates.

VRBO just showed a document that a guest tried offline booking the same dates 18 times and that is why VRBO is charging us more than 1500 USD even if the booking NEVER happened.