Sure, I don't claim that capitalism is the be-all, end-all. And run amok it turns into corporatism, which is no different than fascism, basically. But, regardless of its faults, it's the only system that, if regulated just the right amount, will generate the best solutions. The best systems are a mix of cooperation and competition. Look around, most highly successful ventures these days are open source or something similar. But going outside tech, there's Uber, AirB&B and the like, which employ a similar model. As you mention, China is probably the best example of "communism" which exited its crisis by injecting capitalism. I still think Japan is probably the best nation there is, overall :p

And yeah, anarchism and communism will be the weirdest of allies, because they're both utopian. Even if opposed, they rely on the same thing, which is all people in society need to be the same. One relies on all people sharing everything, which is retarded, and the other relies on all people always respecting all sorts of non-aggression principles, which is again... retarded. None of those scenarios is attainable. People are different, that's why loose regulations based on individualism work best, allowing freedom of association and to form communities of like-minded individuals, while those individuals are still free to pursue their needs. It's never perfect, it never will be, but it's as close as we can get.

And of course these sorts of ideologues will want to shut down speech. Force is the only way it can spread. I don't care, I won't shut up. I might not have live long during communism, but even after it fell, I could notice its effects, I saw my parents rise back from starvation along with capitalism. Again, it's far from perfect, but it's the best we got, and I'll be damned if I won't do all in my power to prevent the red plague from attaining power ever again.