How can I restrict BB10 Z30 in/outgoing calls, texts, email and BBM to a locked contact list?

I'm preparing my Z30 to pass on to my young son. His mother and I have been trying to find some middle ground between no phone and the communications equivalent of an F1 car. Seems unfair to ask a tween to be responsible with such a thing when their brains are still forming.

It is essentially for him to be able to notify us where he's at, or for us to let him know of changes to the schedule.

I've found the parental controls section that restricts incoming to the contacts list, but I seem to have no problem adding contacts when in the parental control mode (who designed that giant, gaping hole?). It appears to provide control over the apps and browsing issues so I don't worry about Facebook, Twitter or YouTube and with any luck, I haven't left any apps behind that provide back door access to those.

There's no contacts-only outgoing restrictions in the software that I can find, but I have the FDN pin from my carrier so I can set that up. It would be nice to find a way to restrict it to the contacts instead of having to add each one on their own to the FDN list.

Are their any 3rd-party apps that allow that sort of contact-restriction? It seems fairly obvious on the surface - incoming and outgoing communication restricted to the contacts list, that is password-protected but finding it seems more challenging.