You said you did presentations with the snakes at his school, right? That's a BIG one. If a school has said the way you transport and handle the animals is safe, that's a pretty important thing.

Seconding what several people have said about the burm though. I seriously doubt the way you're keeping it is dangerous to the kid, but the legal system doesn't like big snakes. If you did keep it, you might have to keep it in a separate room with a lock on the door and another on the enclosure. My family has had some experience with the whole custody thing, and it probably wouldn't be a good idea to have the big snake in a room that your child thinks of as fun/safe to go into otherwise even if he's always supervised.