Meeting seller tomorrow regarding seller financing. What questions to ask?

[Palmer Thomas]

I'm meeting with a seller (and his lawyer) tomorrow to hopefully hash out the details on a seller financed deal.  I've purchased a few rentals, but never bought a house using seller financing.  Are there any specific questions I need to be asking or any points we need to go over that aren't typical for a bank financed purchase?

Here's some background on the purchase:

The seller was in the process of fixing up a house when a medical issue came up. He now isn't in shape to complete the rehab. I've done a few rehabs and the remaining work looks like I can do the majority of it myself. The house has been on the market a while and I'm guessing thats due to the house not being livable enough to get a typical mortgage. The house is going to be my primary residence. My DTI ratio currently keeps most banks from lending to me and since it's going to be a primary residence I don't think I can get a DSCR loan. I've already had some back and forth with the seller, going through our RE agents, and the numbers we currently have are basically a $200k sale price with $100k down and the seller financing the other $100k.

Any pointers would be appreciated.