A:AnswerI don't believe it will shut down based upon time. The best thing with kids is to monitor them yourself and have the phones in one area when they are sleeping. The phones can be charging while they sleep.
If you are connected with Comcast, you can turn off WiFi at any time you like.
A:AnswerNot really sure. I’m guessing it depends on your provider. I replaced the one I was renting from my provider (xfinity) and it seems to work a little fast. Sorry not much help.