My son is 15 years old now, can I leave him alone to stay and go some other place and come back to pick him?

Why not? It's a fun, safe environment for kids. But you would have to trust your kids. I was naughty when younger- leaving places my parents dropped me off at for parties,ect. So I guess on how responsible and trust-worthy your kids are☘

I doubt it with the liability waiver you have to sign.

That's more your call, depends on how trusting of him vs Sky Zone. Me personally I'm not sure I'd leave my child anywhere now of days without knowing the surroundings extremely well and still it comes down to a trust thing with him, the place and you. The place is not a free baby sitter no matter how secure it may appear.

I think so