This passus is there because I'm a private seller.
No returns means: If you decide one week in that for some reason you don't like yellow you can't send back the board to me for a full refund.
No warranty by me means: In the unfortunate case the board dies I won't buy you a new one.
However ASRock NL offers direct support, I'll provide you with a copy of my invoice in case you need manufacturer warranty.
That being said, I'd prefer to sell the board together with the i5 6600k.