I never made any of the claims you are arguing against. Humans have a tendency to take as much as they can, just like every other creature. This is neither good nor bad, it's just biology. I never claimed they lived in "perfect harmony" with nature. There is no such thing as "perfect harmony," but only balance. As human population and technology grow, we become out of balance with an ecosystem and our presence degrades it. In a low tech world this means we simply move on and the land heals, in a high tech world it means we mine the earth, externalize our costs, and transport what we need to subsidize our out of balance existence.
I do not believe in the "noble savage" but I do believe tribal, hunter gatherer peoples exist in a more biologically appropriate structure. When I say "biologically appropriate" I mean that structure is what we evolved to function within. With that said, from my perspective, your points seem just as imbalanced as the "noble savage" ideology, and sound dangerously close to the excuses used to justify the extermination of indigenous people and cultures. There was so much European propaganda during the many colonization campaigns that our history books are still recovering. While there were war like expansion based tribes in the Americas there were many tribes and groups that would fit the "perfect harmony with nature" description. A perfect example would be the Taino people vs. the Carib people of the Caribbean. The Taino were peaceful, by Christopher Columbus' own admission, while the Carib were a warring expansion minded tribe. Overall though, the native American tribes were far more egalitarian than any European society. I know many tribes had slaves, I know they engaged in organized warfare, I know they killed animals to extinction. However, unlike western civilizations, there was massive diversity amongst groups, so we can't make blanket statements to invalidate their existence.
I'm not trying to say that all tribal people were peaceful and lived in tune with nature. What I am saying is these societies were ripe with models that we should learn from and integrate. Lastly, I don't think "no system is perfect" is conducive when trying to critique a system and discover solutions. We aren't trying to find a perfect system, just a better one. And I believe it's good practice to look at all of what's been done, to pick the best of each, design them together, and trial something new.