Weapons are things that can be produced by human beings. As long as they will be humans, you can not prevent those things to exist.
No, but with weapon control laws the probability of being attacked by a person with a weapon is far lower.
It's naive to believe that gun control laws will take the guns out of the hands of those who don't care about the laws. I'm sure they won't. They'll just take the guns out of those who care about following the law.
I live in France, but I've grown up in Brazil. Both have draconian laws regarding gun-control, it's hard to tell which government is stricter on the matter. France criminality rates are much lower than Brazil. And I'm pretty sure that this has nothing to do with gun laws. For multiple reasons which I'll not try to speculate here, average people in France are just less prone to initiate violence themselves than average people in Brazil. They are more "honest", we may say. It really isn't a matter of France having better security forces or practices, of that I'm sure. Most buildings here have no security, I'm yet to see electric fences around houses, people carelessly leave their cars to sleep on the street, I see less policemen on the streets here than what I see in my home town in Brazil, private security is almost non-existent etc.
It's the same thing with nuke bombs on a nation wide scale: If nations followed the pro-gun-arguments, all of them would need nuke bombs until one nation has more/better nuke bombs.
Although I believe the best path to "world peace" is free trade, I'll just quote what I've written above again:
Sometimes I make a comparison that's not very popular, but IMHO it makes some sense: individuals bearing guns are comparable to states which have weapons of mass destruction. No single state with such weapons has ever been military attacked. India and Pakistan used to make war, once both got nukes, both got "calm". I bet the cold war wouldn't have remained cold if it wasn't for the fact that both sides had nukes. Going to war against a state which has weapons of mass destruction is almost suicide, even if you're also a state with such weapons. Trying to assault/rob/etc somebody with a pistol on his waist is also very dangerous, potentially suicidal, even if you also have a gun (okay, okay, I know ambushes and alike remain possible but these are premeditated murders, not general for-profit aggression... it's more rare).
I'm pretty sure that all governments who don't yet have nukes, don't lack them because they "follow the anti-gun-arguments", but more likely because either they aren't capable of building them, or they are afraid of international retaliation - which, by the way, is as hypocritical as the state saying that citizens cannot have guns, only state employees can.