Risky Subject To Deal!!! Is it Worth It??

[Horace Hayes]

I have my first Subject 2 Deal under contract and based on a few variables want to be sure this is something I should still take on.

1. Terms include being added as an authorized user on the account, however the current financing company (Shellpoint Mortgage Services) has been giving the owner a hassle with adding me. 

2. The Owner owes more than the agreed to purchase price so my plan is to renovate it and rent it out until the balance is down to the purchase price, which may take up to a year. Then refinance it and payout the owner.

3. Owner is sickly

The Deal:

Purchase Price: 25k

Renovation Needed: 40k

ARV: 120K

Owner Payoff Amount: 37k

If I sold it immediately after renovations, what happens to the difference of the purchase price to the payoff amount? And If I go with the initial plan to keep as a long term rental while still in the current owners name is this too risky?  Ive already started assuming the mortgage payments since Nov1 to keep the Owner on the hook but if too risky I may need to back out.  Any advice is appreciated!