Well, those are the conventional takes that I'm taking issue with.

Of course, we live in society, not in the wilderness, and morality and civility are socially important. But how do we know society isn't like an insane asylum surrounded by universal truths which the inmates can't digest without losing their treasured insanity?

Morality is useful to fulfill our goals because it keeps the peace, as you explain with social contract theory, game theory, and so on. But that pushes the problem back to whether our goals are respectable in the context of objective knowledge. Why isn't the goal of social peace arbitrary and absurd, given the universe's indifference to our survival? Subjectively, the goal isn't arbitrary because it's motivated, but objectively our goals are futile, myopic, and laughable, if only because death's inevitability turns us into clowns, regardless of what we do in life.

So yes, knowledge helps us act in moral ways. But knowledge also undermines the self-confidence or hubris needed to motivate and to justify the entire social endeavor.

I think your case for morality, though, is stronger than your criticism of the aesthetic interpretation of nature. I agree that aesthetic appreciation is impossible without appreciators, but the question is what exactly it is that objectively remains, and that would overwhelm the last man standing. Surely, it's natural causality and thus overwhelming creativity (and destruction) of the universal plenum (of molecules, galaxies, and so on). Why shouldn't a simplified form of aesthetics carry over, then, to the objective scientific explanation of natural causality/creativity?

If the universe's self-creation or development is objective, why shouldn't the truth of certain universal aesthetic judgments be objective too? Here, then, with a form of pantheism, we have an objective basis of enlightened values even after the death of God which arguably makes nonsense of the traditional moral discourses.

Note that although I'm inclined to push this line of argument as far as it will go, I take myself to be exploring it. I don't claim to have proved the truth of pantheism or the objectivity and transhumanity of aesthetic values.