The most stupid part of this idea is that is requires a list of banned sites to be served to every user.

Even if they would use hashing to obfuscate the banned domains, you can download a list of all registered domains and just test every one of them.

So the average internet user will lose freedom while a cheese pizza enjoyer with some computer knowledge will gain a list of every banned CP site.

You can configure sudo so that it doesn't require you to enter a password. However I would strongly discourage this, since it also allows any script or program to execute root commands without your approval.