No.
Perhaps not so much gta, but other more violent games like call of duty definitely make people more violent, especially kids because we learn a lot of our behaviour from copying others.
Not really, it just made me want to play the game more!
The level of the violence of 'yesterday's' entertainment industry pales in comparison to "today's' blood and gore. Comparing bugs bunny characters and the graphic image of zombies eating someone's brains, or full graphic content of someone being cut in half by an machine gun is not a fair comparison.
There is a increasing level of desensitization that has changed how children view violence, death and gore .. To such a level that there is now some question as to the legitimate correlation between this systematic desensitization and a kid walking into a school with a gun.