HELP: Need to teach owner about benefits of seller financing 1031

[Scott Hollister]

Hello,

Im working on an off market apartment complex with an owner. I know he wants passive income and I wanted to provide that value for him. 

So far I have these Benefits of Seller Financing: 

1. Higher Price: I can pay more because I can get a 30 year term from you, but a local bank will only give me 25%. Also it is too small for agency debt. 
2. Unless you have a higher and better use for the money. After capital gains, broker fees, long inspection periods, re-trades, etc. you will end up with way less. 
3. Installment sale will net you more future yield.
4. You only pay gains on the extent you receive payment each year. 
5. Faster closing: Banks and lenders take months!

So I put this in 1031 because I have a question. 

-Is this correct: Does the seller only pay capital gains tax on the principle payments he receives from me? 

-And can he 1031 that money? The reason I ask is because of this link I found, where it says a contract sale will work? https://www.1031exchange.com/opportunity-seller-financing/

Thanks ahead of time!