The OP would be taking on significant risk getting into an arrangement like this as a short-term investment strategy (1-1.5 years). 

However, the IRS requires a "parking arrangement" to be put into place. 

hahaShe's really going to like the flower bed. 

Classic big PM company that treats your (OPs) arrangement like they're doing you a favor by hosting your home for you, rather than you doing them a favor by letting them make money off of an asset YOU own. 

We provided a 1st position loan, and I arranged JV capital from my consulting company.

I'd speak with them to see if they are satisfied with the arrangement, or if they feel they are being advantaged, which should then trigger corrective action.

It might be useful to combine this with a food serving arrangement where people could order what they want to eat before they get home and it could be prepared for them at low cost. 

What type  of “purchase arrangement” do you have.

*** The leaking areas, or fixing the rotted areas, should be directly spelt out in any arrangements with a roofing contractor. 

When your father passes (or whenever he chooses to) he can pass the house to the successor trustees who have the power to dispose of it-- or arrange loans to buy out each other.