I couldn't let this deal pass me by!

Lending money at 9% seems a bit riskier than making 10% ROE on a property you have owned for 5 years and know well at this point.

if your doing a senior project I would suspect your best and most cost effective landing solution is going to be a local community bank that loves real estate.. in my experience most will want 50% down on the dirt and a ton of experience and a really strong balance sheet.Myself I always pay cash for the dirt this makes finding a lending partner much easier.

(A partnership tax return is due March 15th, so in this instance, the partnership return will need to be extended).2.

Leverage in an IRA will produce Unrelated Debt Financed Income (UDFI), subject to Unrelated Business Income Tax (UBIT).There are plenty of investment options to deploy your IRA funds, but again, using your IRA in connection with this transaction will disqualify your IRA. 

I’m trying to learn as much as possible in a short amount of time to at least prepare me for this adventure and hopefully make it successful.

You don't want to repeat this situation.

Would love to have conversations with others who have had dealings with this court. 

However, there was no formal agreement or contract between us regarding the ownership or any financial details related to the property.

No one can answer questions like this because the strategy depends on the investor's level of interest, financial framework, location, and many other factors.