Earlier quoted context omitted.
This seems like one of the best schemes I've heard here so far. Only part I disagree with is the "no multiplayer online games" - they are addictive, I've lost a lot of time to them in my life, so maybe you're right, but I want to believe moderation is better than abstinence.
no multiplayer online games are for two reason: 1) as you said, they can be addictive since they are designed that way. 2) I have no control over who they are playing with, the sort of language that is/will be used (though I'm a potty mouth so ..) and what it can/may lead to. I feel a lot of people prey on kids via these channels, though I may be wrong. It's just an additional layer, but overall kids haven't complain…
Back then I also joined voice chat with a lot of adult guys who were 10-20 years older than me when I was a teenager, and still all of them were just totally normal dudes who had a long day at work and were trying to relax with some Halo or something at the end of the night. Conversation was always 100% normal.
Internet forums and social media outlets are probably worse in this respect, and especially for girls. That's where I hear most of the manipulation stories coming from, where some poor kid was tricked into sending illicit content that was then used against them, etc.