"Also, my eldest is 6 and already knows you can get to YouTube via browser" That's a good thing, they won't be completely ignorant with computers. You need to

"Also, my eldest is 6 and already knows you can get to YouTube via browser" That's a good thing, they won't be completely ignorant with computers. You need to teach them how to be safe, not keep them away from it. These hyper-restrictive measures are the equivalent of the D.A.R.E program. They will ultimately harm your kids more than any good they could do.