As a dad I would keep making attempts at meeting the parents, ask neighbors if they know how to contact the parents. See if you can get the kid to set up a time to meet them or at least what time they get home from work generally. I would stay in visible to the public areas because I'm paranoid, and I'm always trying to be ready for, as mentioned, possible recoil.

I think what you're doing for the kid is solid though and it seems like he's lonely and needs someone to show interest in his life, and provide guidance.

Or he's a plant and casing the joint. See paranoid with strong distrust of people lol.