I have never used any official property management software (22 units in 2 different entities).

Right now we are considering 10% down at a 7% interest rate, but nothing is official yet.  

Do I need to create an LLC or have a business license in order to be official?

Can anyone suggest an official website to learn more about FHA loans?

The easiest way around this is to not have the seller record the second mortgage as an official "second" lien on the property.

there is no official form per say because the practice is in a gray area of the law, Consult an Attorney to be sure you are within the law or at least their interpenetration of the law. 

Negotiable as to who pays for property taxes, HOA, other maintenance in interim.The idea is the buyer will be able to refinance at the end of the term and thus officially close on the property.When I represent buyers here on Maui I can tell you seller financing is VERY hard to come by, and I take it as a red flag that the buyer's not qualified.

Assuming a loan means working with the lender to officially allow you to become the borrower.  

HAHA yes we are officially under contract!!!

@Kyle Galloway I can definitely provide the numbers we used on the house for the flip analysis but we have not officially decided on the AirBnb option yet.