My 15 year old son stole my husband's credit card to use on a friend's computer to access some porn sites. So, he is not allowed any unsupervised internet use. Will the parental controls - enabling all restrictions work for us?
Yes. Disabling Safari, YouTube, etc will remove the icons from the home screen completely, and unless he figures out the passcode you put on it then he won't be able to get into those at all.