I call myself an atheist, yet I align with much of your thinking.
A few quibbles with what you have written here.
Agree with you that tribalism is a problem, but not the core problem.
Cooperation is certainly in the picture, but it seems to me that not in the way you have characterised it, but I think I can see how what you say may seem sensible to you.
For me, cooperation is the essence of humanity.
For me, as someone with 50 years interest in evolution, it seems accurate to a good first order approximation to characterise all advances in the complexity of living systems as the emergence of new levels of cooperation.
Games theory is clear, that raw cooperation is always vulnerable to cheating, so to be stable requires effective attendant secondary strategies that work in practice at identifying cheats, removing any benefit from the cheating, then return the cheat to cooperative behaviour (Elinor Ostrom did some nice work in this context).
So the problem isn’t cooperation, it is a lack of effective secondary strategies to identify all the new levels of cheating. And there must always be something of an evolutionary “arms race” to such things, proving the ancient maxim – “the price of liberty is eternal vigilance”.
Tribalism seems to resolve mostly on the basis of the systems available to ordinary people to identify cheats. This comes from an ability to accurately identify individuals over time and to accurately recall prior interactions – and results in Dunbars Number – the effective size of workable cooperatives without using technology, and thus tribalism.
It does seem possible to use technology to effectively increase our power to identify individuals, as well as to accurately record, share and recall interactions, and to maintain wide social networks.
With these enhancements, it does seem possible to maintain cooperation at any number of individuals our sun is capable of sustaining.
Add to this, the infinite realms of the possible available to be explored, and there is ample room for any individuals to responsibly exercise their creative freedom in whatever realm they responsibly choose. And there is, as you have noted elsewhere, cascading levels of temporal, social and ecological responsibility within which one must apply the test of reasonableness.
And complexity theory is clear, that in such open systems all boundaries need to be flexible and negotiable (in infinitely extensible dimensions). No firm answers here, no certainty. The only real security comes from the cooperative, and many aspects of this reality we find ourselves in appear clearly to be not simply unknown but fundamentally unknowable (maximal computational complexity, Heisenberg uncertainty, chaos, stochastic, etc).
The science that is real to me acknowledges the fundamental creativity of the process of hypothesis generation, and the fundamental uncertainty in all things real. The unknown, the unknowable, and the magic (as in AC Clarke’s – any sufficiently advanced technology is indistinguishable from magic) must always be with us, should we manage to live for the rest of eternity.
The fundamental issue of our age seems clearly to me to be that market values are based in scarcity, and anything universally abundant must have zero value in a market. This sets up a fundamental conflict between the many positive roles markets have played in our getting to this point, and the ability of technology to deliver universal abundance of a large and exponentially expanding set of goods and services. Such abundance meets the real needs of individual people, but destroys economic value. Hence we see the rise of intellectual property laws as an obvious approach, and far more stealthy are many of the real outcomes of much of what passes as “health and safety” legislation.
I agree totally with you, that there is a fine balance in being human, between being dominated by rules, and falling into chaos – and that region defines what I call responsibility. Having just lived through a 7.8 earthquake here in Kaikoura – I see so much good in people, and also a tendency to break into smaller tribes as the stress mounts.
It is a very complex set of problems you have set yourself.
And having survived a terminal cancer diagnosis, I align with many others here in suggesting a greater focus on self care.