T's can be handled, but I really wouldn't recommend it a ton. Or letting them free roam. It's entirely possible to teach your son that they're awesome creatures without direct interactions. They're much more of a look but don't touch pet and they're much happier chilling in their tanks.
With that said, there are some species that are more docile and deal with handling better. They don't enjoy it or get anything out of it, but they won't readily try to bite, generally speaking. Check out B. albopilosum, B. smithi, A. avicularia, and A. chalcodes.
Even after recommending those species, definitely do plenty of research as to what the proper methods to interact with your T's are and watch plenty of videos to see what their speed is like. My 4" A. avicularia female is sweet as pie but recently molted. I went to mist her cage a bit and she pounced at the side of the container where I sprayed the water. She was hungry haha. This is the same female that nonchalantly walked out of the cup onto my hand when I unpacked her and barely moved almost every other time I've ever gone and done something in her tank. They're instinctual and predictable, but don't ever assume anything with them or you'll be in for a surprise haha. They're very fun and addicting to keep though, I think everyone should own a T or 30!![]()