If a borrower stops paying on that first mortgage, and then the lender goes to foreclose, any equity that might have been had in the property is now gone because default interest, late payment penalties, legal fees, etc will eat up anything left after the principal balance of that first lien is paid.

For example, the one house with $20k of principal left are you trying to cash out refi? 

For a non-owner-occupied property 1-4 units you can use the market value rental income of the property itself to qualify, based solely on Debt Service Coverage Ratio (DSCR) where the rent to property charge ratio is all that matters (Principal + Interest + Taxes + Ins + HOA). 

You go to refinance and find the value of the home to be much higher during times of lower interest rate (supply/demand principal). 

Lets say your current loan principal is 50, and the value of the property is 200. 

This would show month-by-month how the breakdown between principal and interest changes.

I will be the principal manager of this LLC. 

I changed my criteria so instead of wanting to live for free, I wanted to only pay the principal of the mortgage.

Hi AK,I think this is similar to the flywheel principal... takes alot of energy to get it going at first, but then its off and hard to stop. 

Points, loan origination fee, interest rate, down pymt, term, interest only pymts, amortization schedule (including principal), payoff penalty.