I think you have really helped to clarify the go side of this analogy, and I'm grateful for your description of sabaki play and what makes it different from trick moves. I think the connection you draw to rationality and debate are pretty good.

I'm not sure about this, but I think there's another sense in which the term "dark arts" is used on LessWrong: using one's knowledge of common cognitive biases and other rationality mistakes to get people to do or believe something. That is, fooling others, not fooling yourself. For the go analogy, I think this is most closely related to trick (non-obviously suboptimal) moves. Or perhaps the technically unsound but necessary aggressive moves used by white in handicap games to which black often responds with too much humility.