I offered $400,000 which was accepted, and my yield on the purchase price was about 12.75%.  

I accept chocolates if you feel so inclined ;-)

Some require six months of seasoning, while others may accept three months if the refinance is "on platform," meaning you closed the bridge loan with them.

The seller is also very elderly and may pass soon (he’s rather accepting of this fact).

In fact, I could be taxed at 0% if accepting less than 45k/year or similiar.I bet most people didn't know that probably not even you. 

Co-housing communities are currently more "mainstream accepted" especially financing-wise.

Question 2: In going through the eligibility test, the only part I think I don't meet is Step 3--Residence, which requires 24 months of residence over the past 5 years.

Currently working through some (very) preliminary due diligence with the goal of creating a template for 150 & 250 unit climate control buildouts in order to dial in an acreage size to focus in on for land acquisition, and to try and determine the most cost effective & scalable footprint to build as a "test" that can be scaled. 

I had not considered that because I was imaging a deal where they purchased with a loan and the lender would not have accepted excluding issues like this.

Putting all this action into a partnership tax return reduces the risk right back down to an acceptable amount.Second, with a partnership tax return, we can mechanically show your capital contribution (at-risk money) including recourse loan debt.