Seller Financing deal

[Michael Dallas]

Hello everyone I am currently house hacking my first house and am looking to do a seller financing deal. There is a house in my market that has been on the market for over 100 days and has received no interest. There is a tenant in the property that has a lease until next July. Which is very under market value rent which is why they have received no interest. No one really wants to touch it with the tenants already in there. So I have asked if they will consider a seller financing deal and they said they would. 

What I have come up with so far are these parameters:

full list price of 240,000, 3.5% interest, 5 year interest only payments, 5 year ballon payment of 240,000, if I am not able to refinance for full amount or at all then balloon payment is extended 5 more years, they loan me 30k at 6% for renovations that is wrapped up into my interest payments, this 30k will come after tenant is removed next year, they pay my realtor commissions, and when I refinance they will give me 10k min and 15k max depending on how much my closing costs are. 
I know this is a very aggressive offer but they are not receiving any interest on the property for 100 days right now. Does anyone have anything I should add or anything I know before I go through with this offer?? Thank y’all so much!!