Re: Fully Automated Luxury Space Communism
Okay, I'm bracing myself for a bad reaction to this (not just because of the points I make but because I ramble an awful lot), but it's possible that human nature you state isn't all humans, or even most. Or at least it doesn't have to be. The only reason it is, is that since Europeans exceeded their continent and colonised a lot of places, the culture down to a pretty fine level has been about competition.
Pre-columbus North America is a good example of how a happy, widespread civilisation with always adequate resources can have a pleasant culture. They always had enough because they moved frequently. Of course they had to work, but it's the best I've got. They had trade routes and complex society, and the vikings even possibly traded with them at some point.
I think personally the mindset that is required to succeed now does lead to the collapse of empires. That doesn't mean everyone has it, and everyone will have it, though. People point to lord of the flies as a demonstration of human nature, when really it's a demonstration of privileged white schoolkids when exposed to a harsh unfamiliar environment. The Roman empire collapsed because of a few reasons.
Constantine split it into two, east and west. West was the home of actual Rome, which was arguably corrupt and becoming a weaker city, out of a lack of resources. The west half collapsed, the east didn't and it became the Byzantine who survived a lot longer. The Romans failed because they were stretched too thin and didn't, despite their civilization, have enough manpower to protect the lesser side of their empire, which was merely the side that held the name.
Constantine effectively split the empire, moved the capital, and then didn't exactly let the west collapse, but he gave it its own economic system, which failed quickly as all of the luxury goods came from the east, in a typical east-west country split (think Germany, reversed.) I think it was a lack of resources, not an overabundance, that collapsed that empire.
Maybe I'm a hopeless idealist optimist. I don't know. I just feel like every individual human is okay, so the sum of them all will be too, when there's nothing to fight over.