The amount you can deduct for depreciation might roughly equate to the principle portion so the net effect could be that you pay taxes on an amount pretty close to the amount of net cash you keep.The portion of your mortgage payment that is principle vs. interest will depend on a number of factors, but the lender should send you a 1099 indicating how much interest was paid throughout the year which can be deducted on your taxes.

Of course your specific market conditions and your goals and needs always to into the equation.

You cant accept a loan from your parents SDIRA either so that is out if the equation too.

Well, technically any income with no money down equates to infinite returns.

Thankfully no damage to any furniture so that is out of the equation. 

The reason I mention jeopardizing our ability to move is that I had planned to sell our current house and use the funds from that sell as a down payment on our new place so I wasn't sure about utilizing a possible HELOC in the equation to have more access to funds to start out.

Is theoretical appreciation of the propery used in this equation?   

I don't know much about lease hold properties and have been trying to do some research but I'm still having difficulty making sense of the general equation; what good was your $300,000 investment into buying the house when now the lease on the land is up???? 

Some say you are capped at five conventional mortgages, some places allow up to ten, and some base it solely on a financial equation.  

An FHA loan for 300K that equates to a 2200 monthly payment is around a 5.5% interest rate.