Skipped the last 8 pages, this may be a bit misinformed, but...
Considering the population of America, can all those people really be trusted to make decisions regarding the use of a gun, that would be the most beneficial to society? By that I mean that shooting up a school is not very beneficial to society, as is shooting up a mall.
I was reading the entire first ~8 pages, and I never saw the word "trust" being used. That's what it is about in my opinion. When you have one person in your country, then perhaps. But when you have 313.9 million people, there are going to be people who you can't. Probability-wise, It'll be inevitable that someone will simply misuse guns due to their persona, and just because of the fact that we're human. Maybe some people are naturally cruel, or simply like to cause trouble, or they're just plain stupid and are easily influenced. One can increase education about firearms, which may reduce the issue, but you can't remove the problem completely. If America is willing to accept this 'price' they must pay to keep the gun market open, then that is their decision.
Really I think that everyone who wants a gun should have to go though a extensive system which would then decide whether or not the individual in question should be allowed own a license for a gun. Nothing bigger than sidearms.