Is there a shut off for young passengers and where is located?
No I don't think there is a shutoff. Though, I think dealers have installed them. Try doing a search.
It's a pink and yellow connector behind the passenger airbag. I accessed mine on the 456 through my glovebox. Make sure to shut the battery off before disconnecting. Also, your airbag light will still be on after reconnecting - I don't know how to reset it.