Miguel you seem to have had lots of horrible experiences in America and for that I'm truly sorry. But you do seem to have spent most of your time in the worst areas of America and in a tumultuous time in our history to boot. I don't doubt your experiences but America has changed a lot in 40 years.
Luke, I'll let others pitch in before I say too much more, but let me just assure you that most of what I wrote about things I've experienced and seen did not, if you look back at them, occur to me personally. Yes, I've seen a lot of, and experienced some, bad things. Most of what I've seen occurred to others: friends, family, strangers on the street. And I've lived in some very safe and relatively uneventful areas of the States, too, but my family comes from Brooklyn and the Bronx (others in Harlem), so yes, I've necessarily seen the worst of what the States has to offer. Another part is that I am not white... I look like a Chicano and was often stopped, and a few times roughly manhandled, by the police, because I look like a Chicano. That's the reality of not being white in America, especially during the 70's, 80's. and early 90's. You can be a stranger walking into a posh bar in La Jolla, California (which my brother and I did in 1983) and if you're white no one will give you a second glance, but if you're dark, and, heaven help you, black, the reaction will be totally different. My brother and I were clueless at the time as to what our entering that one place would entail, but if it weren't for this middle-aged guy quickly inviting us over for a drink and telling us to lay low, I don't know what would have happened to us. But that is what dark-complexioned men face everyday in America. And guns are often involved. A disproportionate number of blacks and latinos and Indians live in those areas that you call "the worst areas of America". They usually have little choice.
Have most of my experiences and encounters in the States been bad? No, not at all. Most of them were just like you describe above. But we're talking about the gun problem here, right? We're talking about what motivates Americans... the country as a whole... to do what they do and to need guns the way they do. So I made generalized observations about the worst things in the States, since that is what the need for a gun is based on, no?
As to comparing countries... well, I was asked to make the comparison, so I did. I don't see how you can make such comparisons without making big generalizations about one country and the next. The truth is other countries are on the whole much safer than the States, and feel that way, too. Of all the countries I've traveled and lived in (and I've been to a lot of countries), America feels the most dangerous and most prone to violence. That's just my observations, of course, but a lot of other non-Americans will tell you the same thing.
I also wanted to add that statistics don't influence the perception and attitude in a country. Even both of you, Luke and Tom, were shocked by what the statistics showed you. Using and advocating the need for guns for the most part grows out of people's perception of danger and wrongdoings. So if the statistics are true then the need for guns is based almost entirely on paranoia. I do not think paranoia is a proper basis for arguing for the advocacy of guns. In fact, I'd say that the statistics show that then that there is no need for guns. The Newtons still keep happening.