Your objection to the Soviet Union boils down to the idea that it can't be considered a failure of socialism because it was a variant of  Marxism, and Marxism is not real socialism in any form.

Your objection to capitalism has three parts, one is standard issue crude Marxism. The other is that it fails to take into account environmental externalities (a purely political and regulatory issue that can easily be done within the capitalist framework). The third is that it shares all the faults of Marxism.

Isn't there something a bit strange in so utterly rejecting Marx's vision while embracing his critique? Colman has mentioned that there is something a bit vague about all this, but given the approach I don't see how it can possible be anything other than incoherent even if fleshed out.

Finally, like all expressions of radical environmentalism that I have ever seen, this one marries a radical environmental agenda with a radical sociopolitical one. Yes, I understand that for their proponents you can't have one without the other. Somehow it seems to have escaped them that all it does is make change even more unpalatable and more painful and difficult to implement; adding the massive upheaval of socio-political revolution to the wrenching changes required by the environmental constraints means all the more resistance and suffering.  Given that, the fact that you've already taken the first big step down the Leninist path in point six doesn't bode well.