Returning to this very belatedly. I actually agree with most of what you say here, and the points of disagreement are not especially important. However, my point WRT the original analogy is that it doesn’t seem to me to be compatible with these insights. If the general state of the world is equivalent to an emergency in which a man is drowning in a river, then the correct course of action is heroic, immediate intervention. But this, as some of your quotes, is totally unsustainable as a permanent state of mind. The outcome, if we take that seriously, is either crippling scrupulosity or total indifference.
The correct move is just to reject the original equivalence. The state of the world is NOT equivalent to an emergency in which a man is drowning in a river, and intuitions drawn from the prior scenario are NOT applicable to everyday existence.
Though I didn’t participate in this exercise, I enjoyed reading about it and looking over the answers below. It put me in mind of a particular meta-point, which is that predictability turned out to be the key. The most profitable answers all hinged on noticing which categories the thaumatometer gave accurate readings for, and using those to minimize uncertainty.