Thanks, buy the way for posting that DT series, and for answering my questions. Both have been very helpful.

You're welcome!

I would be interested to hear how the algorithm described in DT relate to action (it can't be that they describe action, since we needn't act on the output of a DT, especially given that we're often akratic).

Yeah, a human who consciously endorses a particular decision theory is not the same sort of agent as a simple algorithm that runs that decision theory. But that has more to do with the messy psychology of human beings than with decision theory in its abstract mathematical form.