Only you know your son Oz
I have been a youth worker for over 15 yrs and in my experience, example is the best teacher. If you have your life together, are stable and contented, your son will compare your life decisions with the jws he sees in his congregation. When my son was still in, I didn't talk about jws at all, just my life and his. You are spot on in "having his back". When the elders turned nasty, I was there and now he trusts me totally and is old enough to "have my back" as well.
I never wanted to be his mate, just his dad.
Good luck