1) It becomes a problem when gaming interferes with your life. Bear in mind for every gamer with a dangerous addiction, there are a million who are absolutely fine.
2) I would try and encourage them to game less. I wouldn't try to make them stop entirely, because that is impossible and, frankly, unnecessary. Just do it in small steps.
3) (you wrote two twice lol) No, because I have heard this before. There are people addicted to gaming, gambling, drinking, fast food, chocolate, football etc. There are people addicted to pretty much everything on the planet. Gaming is unfairly singled out because people need something to blame for their own stupidity. It used to be rock and roll, in a few years, maybe it will be virtual reality. Like I said, the ratio of dangerously addicted gamers : non-dangerously addicted gamers is 1:1,000,000.
I am addicted to gaming in that I love it, but I would not skip meals or lose (much) sleep because of it. In the end, all you have to do in most games is press the START button and take a break. It'll still be there when you come back.
(Former) Lead Moderator and (Eternal) VGC Detective 
