I've looked online but couldn't find a lease that has anything about not being able to claim ownership of the property, most were focused on rent payments which I'm not concerned with.   

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.

My favorite is when investors reach out to me, a DSCR mortgage broker, want me to find them the best financing, and then say "but I want to save on closing costs, so I'd rather not pay a broker fee".Those are my favorites lol 

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.

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

Mortgage rates are affected by how much banks need to pay for the money.

I will be able to cash out my original down payment + 30k more if I wanted to but as im going through the process I was wondering in the future if I pursue investing full time how do you still get approved for mortgages?

As with all online revenue estimators, allow for room for error.