Ability to repay - can you as the borrower afford the payments based on the loan amount.Typically they will not take into consideration the mortgage on a new property that has not been taken out as that is new.

all materials, all labor costs to others, Not you, utilities, interest payments, permits, licenses, auto/truck expenses, tools needed are all deductable. 

So the problem is you wont be able to source the down payment as coming from the seller (most likely), but you can certainly add as many junior lienholders as you like, after the fact.

Some gurus tell practicioners of sub-to to hide transaction from the lender by saying the lender doesn't care as long as the payments are being made.

Which do you think a tenant will pay first - their car or rent payment?

Even if you only owe $26,000 on the loan, your payment will still be the same.

I usually end up with a list of buyers with down payments but I don't have any more inventory for lack of inventory (capital).

This way the payment never fluctuates.2.

So same thing I paid my monthly payment to my bank and kept the rest.

For example if one partner brings the 20% down payment and the other will do the labor for renovations then what would be a reasonable split be.