I just looked to how underwriting is done with mortgage qualifications.

And I think if we re-evaluate properly unemply is closer to the mid 4s. 

If the buyer foreclosesa. if the house is bad quality and dealing with Lennar warranties is now my problemb. now I have to be the one to make the mortgage payments to Lennar3.

Taking cash out by way of a new mortgage is not a taxable event.  

I’m selling a home for $330K if I offer owner financing, I’d ask for $130K-$150K and then the remaining monthly amount until the mortgage is paid off.

This means you are doing it strictly for the cash flow.If it were me, I would go the ADU route, Rents could be comparable to the condo without the HOA dues (yes higher Cap-Ex but those are long term expenses), and with everything on one property, things are just easier to manage (one mortgage, one property tax bill, one insurance, etc.). 

The issue with BRRRR is that the refinanced mortgage wouldn't come close to the "1% rule". 

I own a house in OH (no mortgage) with my relative.

Is the ground properly graded away from the home?

There may still be other encumbrances (judgments, priority mortgages, taxes, or liens) that survive the sale.