Communism

So do you believe humans are, at their core and regardless of system, predisposed to destroy the planet?

Yes. That's what happens when a species is too successful with reproduction. Any ecosystem can be completely destroyed if the balance is thrown off. Too many wolves? They kill all their prey and starve. Not enough wolves? Prey animals wipe out their food source and starve. A balance is necessary to sustain the ecosystem. Humans have completely disregarded and destroyed that balance for themselves.

As to your other points I'll admit I lean a little towards omnicide. But it's because I know how much better things could be if humans could simply work together. I try my absolute best to change the world for the better but I also know humanity and I've seen firsthand what humans do over slight disagreements. Truly deep down I just want everyone to work together towards a brighter future and I strive to help that happen but I've seen time and time again that that's not going to happen. So I continue to try to help while also accepting that this species is parasitic and would gladly burn the world for better comfort for a short time.