We’re custom home builders in far west Texas (GPLLC) that recently purchased 9 acres for development (purchased in the name of GPLLC).

We properly recorded the assumption between us and the other individual, and the lender and other individual recorded a notice of consent to loan assumption.I don't see any assignment language in the document.The note states that we "promise to pay to {owner, husband and wife, as tenants in common} (information on principal sum, interest, and currency), at the office of {address} or at such place as the legal holder hereof may designate in writing"To me, it reads as if they can change the address in writing, but not who we are paying.Later, it states that we shall pay "principal and interest payments of {amount} on the 5th day of each month to the office listed above, and, at the election of both {husband and wife}, or the survivor of them, if not called sooner, which election shall be made in writing, in one lump sum payment of principal and accumulated interest on {date in future}."

IE - if insurance companies misprice a product, they first correct it by modifying the cost to NEW customers. 

You are making an ASSUMPTION that because their yard is unkept they are motivated, right?

This contract contains most of the iterations you would want to see in a contract, and if you want to add custom constraints in the contract you can add them into Section 29.

This is a mother-in-law / guest wing of a custom built passive home (self sustainable from solar,high efficiency electric/insolation) very pretty, and feels like you are in the country for sure with some mountain views on the clear days.

I do like their customer service  I work with Eric who is very responsive, & Kaaren is also available  

Can anyone confirm my assumptions or give me alternative advice?

Rebuilt entire home with full new custom floor plan adding a 2nd full bath and tripling size of kitchen opening out to back yard giving it more light throughout home.

Quote from @Chris Napierala: Bluetent, lodgify, littlehotelier, and others.I would build using a template site like one of these and then work on your own custom site as time allows, if necessary.