I don't think I'd want to be on the opposite side of him, I'd rather be in his corner but most of these deals it means he's not necessarily on the same side as you if it's being offered to you and he's not taking it.I avoid these academies and masterminds of the sort.

Protection from lawsuits is a big item to consider as well, especially in higher price range properties. 

I’d like to leverage my savings to be able to retire early.

If the IRS classifies the property as nonresidential, it could be 40 years.

Quote from @Clint Miller: Seller financing opens up great opportunities for real estate investors, but coming up with the down payment can still be tricky. 

However, there may be a commonly expected way of handling it in your area.

That is what can be difficult if you are looking at automation of this step. 

As I see it, the only ways that real estate pays you well in the first 3-5 years is low to no leverage or a strategy that requires more work (short term rental, mid term rental, rent by the room, etc.).  

I would guess an older home might be more cost to insure?

(I've not done another capital gains exclusion ever.)Or would the sale be considered to have already happened 3.5 years ago, the owner-financing be considered a loan, and only the interest on the loaned-out money be taxable?