Have you seen the following dissertations: Dash (2003) Caveats for Causal Reasoning with Equilibrium Systems and Voortman (2009) Causal Discovery of Dynamic Systems?
My dissertation was initially going to be an extension of this stuff. I ended up writing something very different, but I still think about these problems off and on. If you have thoughts that you would like to share and discuss, I would be glad to chat.
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.