Hardware

You generally have to pass a background check.

This is what I am refering to (generally). Having a de facto optional background check requirement is not a serious approach to responsible civilian gun ownership.

To my understanding, beyond the private seller loop hole (which again de facto negates the background check requirements), I believe there are also other loop holes. Mexican cartels in particular have been documented to use multiple other loop holes that enable bigger throughout versus private sales.

As you mentioned yourself, the safe storage requirement is unenforceable so I don't see how it's relevant.

There are many other externalities to irresponsible civilian gun ownership beyond school shootings (I lived not far from Detroit and visited Flint and similar areas outside of the Midwest).

Note that I am not arguing for or against civilian gun ownership. Nor am I suggesting that Hollywood style scenes with Arnold Shwartznegger grabbing the gun in the store in Terminator is the issue here.

I am arguing that based on my experience of living in the US and research on Mexican drug cartels, it is reasonable to state that a large part of the US population are openly malicious when it comes to responsible civil gun ownership.

Furthermore, much of the polemics around "armed citizenry" are sophomoric and are primarily motivated by theatrics and self-indulgence via claims about "supporting freedom" and trying to portray oneself as being an "independent individual".

One final point, what I am writing might come off as Anti-American; but I disagree with this characterization, from my perspective I am merely discussing a factual point. There are good and bad things in every country/culture.