I agree with your assertions to this point, particularly a lack of metric for events prevented. However, I see your analysis of human nature as deeply flawed. The simple version is that it is ridiculous to assert that guns make us more civilized. Guns just make you feel safer in an uncivilized society, nothing more.
Firstly, it is the result of your environment. You apparently assume that because you have seen inequality, that only inequality is possible and do not address, let's say Switzerland. Here is a society that has avoided wars for centuries and where the citizens on the lowest strata are not so far below those at the top. Gun ownership is very high. It occurs to me we need to make sure we agree on the definition of "civilized" for the sake of this exchange at the very least. However, I think that what we both mean would include Switzerland as being very high in a list of most civilized nations. Some would argue this is due to gun ownership, but as can be shown, there is also very high equality and equal opportunities for people to advance.
Also, you assert that man is an apex predator with a massive capacity for malice, as if this is intrinsic and not a product of environment. You then point to the very inequality I allude to, taking my own premise into your argument. So we agree there is a correlation between inequality and and what we both seem to regard as a lack of "civilization". However, I posit that you have causation backwards. It is the inequality causing the environment which guides the behavior. As surely as there are some with an innate tendency for malice, it is in the nature of every human and demonstrable in most other species the capacity for compassion. The descent into the madness of our uncivilization, in its abundant malice, has been a gradual one.
At the core, what I suggest is that "survival of the fittest" is an inapt description of natural selection. Mutual aid is a factor of evolution and we fare better as a species, in cooperation. Furthermore, whatever in our nature that makes us apex predators is not applicable to our treatment to each other, at least not evolutionarily, but only to our ecological niche. In conclusion, I do not suggest any change or even focus on gun laws, keep your guns, get more guns, sell guns and make guns, idgaf. The debate about civilization is not one that guns can address. Killing does not come naturally to all or even most. Violence does not come naturally to all or even most. The traumatized are the violent. Killing and violence are aberrations, but we have gradually slipped into a society wherein they are increasingly commonplace. I know this from experience and believe it, this is the core of my argument.
Guns don't make a society more civilized, equality does, cooperation does. Guns also do not impede equality or cooperation. These are two separate arguments for two separate debates.