Are your rents equally high? 

If not it’s equally easy, I’d just caution you make sure the sandwich part of the LO is legal in your state!

"I, Bob Smith, promise to pay Jim Jacobs a balance of $XXX,XXX  which accrues Y% interest per annum compounded monthly, in equal monthly payments of $ZZZ over the next 20 years, etc". 

If you both has equal amount of investment numbers from the beginning then that point it’s clearly 50/50 however if you invest your personal loan into the business then it should increased your portion of investment which means you are solely responsible for loss and gain.This is my understanding.....it’s hard to have family members as a business partner ( Bittertruth ) Good luck !

Which with your suggestion would be me finding a property that the purchase and rehab cost equaled what cash I would have on hand from both my savings and refinance.One last question if you don't mind.

Roughly it means that all tenants are equally responsible for making sure all lease terms are fulfilled (including rent payment). 

No two applicants are equally qualified.

Make them equal partners with voting rights.

Beware of your "turnkey providers" not al turnkeys are made equal! 

I’m ready to accept but In waiting for their reply, I found out there’s a currently a tax assessment on the property for the sewer bill and an outstanding water bill for equally as much.