To me the premise of your FED (the amount outstanding) is now incorrect (...probably).  

The state where you file your fed tax.

I also charge an application fee (don’t tell the feds). 

Buyer 1 goes about his payments and see's his mortgage rising since he wasn't aware that the FED is raising rates for the next 3+ years.

Pen Fed may be willing, if you hold the property in your own name.

I assume that I can take possession (change locks etc) and perform structural repairs sufficient to bring it back to habitable standards but my question is does that include sprucing up the property itself ie tree trimming grass cutting and the like to maintain neighborhood norms?

Typically tied 1-to-1 to prime, which is what goes up every time you hear on the news that "the fed raised rates again." 

I need someone to cut grass in kc missouri once a month

Even mowed the grass for him all summer while it was vacant and did work to help him get it rent ready.

Which equates to heirship issues, leins from the city for keeping the grass cut, interest in those leins depending on how old they are, and a host of other potential hiccups.