No. In order to let a video game do that to you you must be a bit 'unstable' before because lots of people play those games but know the difference between reality and fiction.
When young people hurt others it's mostly because of other factors, for example being bullied in school. But it's harder to work on social issues than just blame it on something like games, that's why politicians prefer to shift the blame on violent games.
No but not really.
For mentally stable people, it shouldn't affect much.
But for those who are unstable, violent video games and movies and music videos... make them think that using violence to solve problems is the norm, is what should be done. Also, it glamourizes the idea of using guns, weapons...
It's like growing up with violent/abusive parents will likely affect you one way or another. It does not mean that you will 100% become violent or abusive, but maybe you will tend to yell, get angry easily... I dont know how to put it but I hope you get what I mean.