There ought to be a term for the difference between considering an action in and of itself and considering an action along with its game-theoretic effects, potential slippery slopes, and so on. Perhaps there already is. There also ought to be a term for the seemingly-irrational-and-actually-irrational-in-the-context-of-considering-an-action-in-and-of-itself cooperation-norms that you're so strongly arguing for defecting from.

In the consequentialist ethics family, there's act consequentialism, rule consequentialism, and a concept I cannot recall the name of linked here or possibly written here long ago of what I will call winning consequentialism. It dictates you consider every action according to every possible consequentialism and you pick the one with the best consequences.

I think it was called plus-consequentialism in the post, or maybe n-consequentialism, but it seems to capture this.

But your failure lies in assuming that winning consequentialism will always result in this sort of clean outcome. Less Wrong attempts to change the world not by the sword, or by emotional appeals, not even base electoralism, but by comments on the Internet. Is it really the case that this is always the winning outcome?

An experiment: Suppose you find yourself engaged in a struggle (any struggle) where you correctly apply winning consequentialism considering all contexts and cooperation norms and find that you should crush your enemy. What do you then do?

Your consequentialism sounds suspiciously like the opposite and I wonder how deeply you are committed to it.