Family has made all all the mortgage payments in the meantime, and incremental improvements to the property over time (added back deck with ramp, double paned windows to all bedrooms and living room).

Because it's raw land...there wasn't much I had to do to it...but after looking at the local comps and how other agents were marketing properties in the area I knew that they were over pricing these properties AND doing a terrible job at marketing the properties with the descriptions & images. ( So I did the opposite by pricing this property correctly, Improving the images, making a video about the property and building a very descriptive ad copy.)What was the outcome?

Factor in the expected life of major improvements and their replacement cost.

@Ernie Sturzinger I guess to answer your question...not taking cash from the deal is perfectly fine and even a wise decision...this means the building needs to generate cash flow...you just need to leave it in reserves or make planned improvements...long-term equity is much more important than monthly cash flow.

When the house needs work, I work in comments that I'll be improving their collateral to justify a lower down payment and rate.

Then you can work as a staff member for them and you would operate under their license and direction.  

The idea is go 50/50 on the down payment and any improvements to the property (likely kitchen and bath upgrades).

Your credit will improve over time, (I don't know the exact circumstances) and maybe it's better to wait a year to see where this all sorts out.....?

Do I subtract all improvements(costs) from the sale price.

Nor does it factor in your ability to force appreciation by improving operations and raising NOI.