They aren’t secured to a footer, they are just kinda jammed between the basement floor and some of the major beams on the bottom of the house.

Look into a hard money loan so you can get the rehab budget covered, and make sure the rehab budget is non-dutch so you do not pay interest on the rehab budget until you begin to make reimbursement draws.

Also, does/can this work with only raising part of the money via private money and the rest via a DSCR loan?  

With the landscape of today's interest rates how would you go about marketing a property for sale that has an assumable loans?

The issue with our loan would be that there is no collateral since our loan amount would be more than the land value itself if anything were to happen.

Hence if something like this happens and you collect the security deposit, you have that paperwork to fall back on if it goes to court. 

A portion of the payment is going towards loan pay down.

It depends on the type of loan you are applying for.

I have no credit debt and $12,000 of student loan debt I'm looking to pay off within the year.

All VA, FHA and USDA loans are assumable and even a few Conventional loan products out there are assumable as well.