While I see that the world has changed since I was a kid, and parents have concerns that didn't apply in those days re social media, the comprehensive nature of what you seek to do in your post unsettles me somewhat.
What age are the kids? Kids, early teens, mid teens?
At what stage do you think to teach them about personal space, privacy, and boundaries, and enforcing boundaries? Where do they have the right to say "no", if at all?
At what age do you think they have a right to their own media without oversight and supervision?
When do you expect to be able to teach them to 'separate' from you, which is part of the psychological function of the whole experience of adolescence?
Certainly, (and yes, it was a while ago, with different threats and different advantages), when I was a teenager, any letters that ever arrived for me were left on my plate, sealed, until I returned home from school and opened them.