Without many restrictions. Ok. You can consider Americans violent people if you wish, I'm pretty sure none of us give a shit. The violent places in the United States are limited to some urban centers where the violence is almost entirely driven by illegally owned firearms and gang/criminal elements. These guns would not be confiscated in any law you could write. All you'd do is take them away from folks who already follow the law.
You completely missed the point on the first argument. Whether you or I give a shit is irrelevant. If you take two groups of people (Americans and X western country) and compare them side by side, then say that gun availability isn't a factor at all, then look at the statistics. What is the conclusion?
You're saying that there are areas of US where police have no power whatsoever? I doubt it. Give the police the power to search and seize, you'll see results.
Go and take a look at all the spree killers, vast majority of them had legally purchased firearms. The illegal firearms argument is true in some states and false in others, according to PolitiFact. But the idea is to reduce the total numbers of weapons in civilian hands, fewer weapons means it's more difficult to illegally obtain one.
Post Soviet era (early 90s) was a crazy one, you could buy an Kalashnikov (AK-47) at the central market by talking to the right guy. The police cracked down on that business and that's a good thing. In US that seems to still be the norm and I can't figure out how people are defending this.