The lender would be the mortgage holder on the Deed on the property I own, but not a new one I buy.

We paid cash for it, so there is no lien holder at this time.

Usually preferred holders get less 'upside' but more protection.And how would you actually structure a limited partnership for every single property?

A due on sale clause basically says that if the borrower transfers title to the property, then the note holder has the option to call the entire loan due.

We will have a 1st lien with GC/title holder. 

The problem with acquiring and rehabbing tax lien acquired properties, I have found, is that during the "barment" period, the tax lien holder cannot legally step foot on the premises or do much in way of improving or securing the property.  

We are allocation holders for D6, other fuels, grains, metals, and other commodities.Vetting is required of each new buyer.- J Johnson

I suggest you do not allow that, since you probably are not set up to accept credit cards, since there is a fee to the merchant to accept a payment via credit card, and since the card holder can dispute a charge. 

Twice I left the life estate holder interest alone.

He is a lien-holder, which gives him certain rights under certain conditions -- like being able to foreclose if you don't pay your monthly payments.The best way I've found to explain seller financing to a seller is to ask if they've ever purchased a house with a bank loan.