My question again stems around using seller financing to allow them to receive a consistent monthly pay of X amount and delay/lower their tax bill in the short term instead of going through a lender to borrow 800k+ causing my mortgage to be significant part of our income roughly 40-50% of take home -  which we are approved for LOL.

Research ways to use your education to help you qualify for a loan (did you know that some lenders allow college credits that translate directly to the line of work the graduate pursues to count towards work experience, accelerating the borrower's opportunity to get approved for a mortgage?). 

Just because you get a loan approval does not always mean you should move forward with it.

5) If approved, how much will they want upfront, when can they start and what's their expected completion date?

The builders loan couldn't approve us for the amount we need to get, but we had a loan broker find a loan for 10% down DSCR with a 2nd home status instead of investment home.

@Anthony Becerra I believe you are looking for a pre-approval letter.

Start networking with local agents and investors for insights, and talk to a lender to get pre-approved to understand your budget.

.: Has anyone else submitted receipts to Airbnb for damages, let's say for $200 and they come back and say that they approved reimbursement for $150? 

Q2 is most important: If the mortgaage is upside down, it would have to be an approved short sale and that could take a very long time to rectify.

I would suggest the first thing to do is get connected to a lender that can fund your projects across the country so you know you are pre approved and have no delays in the purchase process.