Srebrenica is overrated, and at least we dont start resource wars every five to ten years that are hidden behind a mask of "war against terrorism" . As we Serbs would says " Whore talks about moral." ..Check your backyard first!
Srebrenica is one of the worst atrocities ever committed. Serbians will be forever tarnished by that act of genocide.
Why should I be marked for something I did not commit do nor anyone form my family? If you could draw parallels like that than same could be said for both Croats and Bosnian Muslims, and many other nations including Americans (remember Native Americans eh?), there is a name behind every crime. Pure ignorance from you.
The same arguement could be used for gun ownership.
Why should law abiding citizens be punished for the actions of others.... 
Is missing the point something Americans are taught at school, or is it genetic?
Liberty isn't an absolute, i cannot be, i hope you can see that in a few examples i've given. freedom and liberty are virtues in themselves.
So it's really a question of what counts as a legitimate curtailing of freedom. The freedom to carry a weapon verses a statistical increase in the deaths of innocent people. People will die so some can pursue their habit of carrying a gun, that's the real choice.
In my case, it could be both. 
Your first example fails because my freedom to own a piece of metal doesn't harm anyone. Your fist hitting my face might cause me some harm.
Punish the criminals, treat the mentally unstable, and establish a society where people have enough respect for self and others that such crimes become a thing of the past.
I'll take your last point first.
Constructing a society in which people have respect for self and others to the extent that crime doesn't exist is a fantasy. There's never been such a society and there never will be. However, some societies are more violent than others-the US is a violent society-at least in contemporary terms. I'm using violence instead of crime because what counts as criminal in one generation can change ie persecution of witches, homosexuals etc.
Given that human nature and our capacity for violence and aggression is a constant (males always commit more violent crimes than women etc) what can be changed is the environment, and that includes the moral framework individuals find themselves in and access to harmful tools. It makes no sense to undertake a shift in behaviour against violence without an associated shift in the means to do violence. Of course someone could use a bath brush to kill someone, but if the have a rapid fire ammunition, or hand grenades for example, the few who's behaviour cannot be accounted for, even in a relatively low crime rate society like that of Singapore, is at least mitigated in terms of the amount of damage they can do.
Regarding your first point.
Swinging my arm may or may not harm someone, just as my using a hammer may or may not harm anyone, or a gun, or a Kalashnikov rifle, or anything else. But in a society where nearly every adult could legally own a Kalashnikov, i'ld be far more fearful of the consequences of crime than i would be living in one that outlaws all weapons. The arm, hammer, gun, Kalashnikov are all tools, but some tools can do so much damage that you're freedom to won one, makes my existence more suitable to termination.
I've just heard on the news there's been another tragic shooting, unfortunately and with deep sadness that only helps make my point.
