I have never missed a monthly payment. 

So if you ever sell down there, make the payments in the US.4.  

They also want a priority lien on the property.It sounds like you are looking for someone to fund your down payment, I would be looking for an equity partner over debt as nobody likes to lend money in insecure positions, especially when a borrower lacks skin in the game.How much are you planning to come in with yourself?

Can anyone recommend software which would accept monthly payments (from me to seller) and create proper 1099 forms for tax purposes at year end? 

Each method has a cost in both time and money.  

-Cash Back on debit card payments (THIS IS THE BEST)-Higher APY than is typical on checking accounts 

Would that method work again?

Use a 2nd position heloc to absorb your paycheck, once your paycheck is entirely paying off your heloc, then it is safe to advance $3000 or $5000 extra against your heloc to make a principle payment against your 1st position heloc.

A “contract to hold” binder payment equal to a month’s rent would also be collected at that time.

If she doesn't pay the bill refuse her next rent payment and evict her.