Concert Grand Pianos

I have a 5 year old son that I would like to learn the piano. I’m 25 and have played since I was 5 or 6 … I know how to sight read and understand musical theory. I researched the Suzuki method, and I agree in it with some principles, but I think it fails in some as well (particularly sight reading). I have a grand and a digital piano, I was thinking of color coding the notes of C major, and writing out the colored notes on staff to songs of his liking. I don’t want him to feel forced, or like practicing should be a chore, so I really only want to focus on him learning songs he likes right now. Should I insist on good hand positioning, or just let him peck the notes for now so as not to frustrate him with mechanics?
He doesn’t show a whole lot of interest in the piano right now. When I was his age, however, I didn’t either, and my parents sent me to piano lessons with my older sister. I never felt forced, but they encouraged me to play. When I got somewhat decent, I loved it and have never looked back. Everyone in my family plays music, and I want him to be able to share this same great experience. I just don’t want him to get discouraged from practicing like so many people do.