The other part sounds like it was a rehab and now held for sale, which does not qualify for 1031 Exchange treatment. 

That sounds like a great plan!

Now taht real estate has gone back to the good ole days of not being an appreciation machine and a good investor needs sound fundamentals in managing and overseeing the properties - now you are given the wave of "creative finance" which comes off as its easy to get a home but it will be interesting to see how these people are fairing in a few years of mismanagement of these assets. 

It sounds like the agent you worked with may not have been acting in your best interest, and I would strongly recommend finding another agent.

The property is paid off so you have options.Based on what you’ve shared, you carrying the note sounds like a viable option.Have you considered seller financing?

And sounds like a good set of options you are looking at.Here's some data and visualization on recent trends in some of the markets mentioned here.

If the work needs updates, that’s where it can add up, but $30K sounds like a reasonable cushion based on what you’re describing.It sounds like a solid deal, especially if the cash flow is good.

It sounds like they just sent you to a lender and builder and maybe they got a piece from each?

Sounds like you've got a great mastermind!

(I am a silent investor, the developer is doing all the heavy lifting, and we split profits at the end)It sounds like you’re being really strategic here, which is smart.