I think given you're enthusiasm for kites and all the cool things you can do with them, your son is bound to catch the bug too. It's too much fun. There's something very zenlike in flying single lines too. Quite carefree.
I'm sorry to hear your "home field" has been built over. My hometown has been built up alot over the years and I know how that feels. I grew up with lots of farmer's fields nearby. My "home flying field" though, was the beach 7th & JFK, fwiw. Makes me sad to see the hotels I stayed at either gone or turned into expensive condos.