Thanks. I hadn't read much on the subject before. Being able to go from that observational data and those causal assumptions to calculating precisely the expected results of an experiment you haven't carried out is amazing! I second your recommendation.
Michael Nielsen has posted a long essay explaining his understanding of the Pearlean causal DAG model. I don't understand more than half, but that's much more than I got out of a few other papers. Strongly recommended for anyone interested in the topic.