The R&R states only that solid or hardwood flooring must be installed with sound dampening material. 

The existing structure and the materials.

But you have to actually read the material yourself, and show up for class occasionally.  

Alternatively if Randy does not care if he has a recorded mortgage then there is no problem with him being on title even if he is a lender.

This site is amazing at turning learning material into actionable knowledge!  

Outside of the above, a private lender may also be an alternative for you.  

Alternately, use your contracting skills as what you're bringing to the table. 

Materials - could have saved on a bunch of items, now that we know where to go (we bought all the materials and also did the landscaping).

You don't want to buy and then find out it is illegal as a duplex.As an FYI if you wind up doing cabinets check out Building Material Outlet they have a location in Minneapolis they were Waaaay less then Home Depot here in phoenix, less then half the price and carried a lot of cabinets in stock here at their Phoenix location.BMO

Shoddy subcontractors, substituting poor quality materials, etc etc are commonplace.