Also... are the real-time publishers below doing anything different than regular publishers, given that they aren't actually working in part of the pr2_controller manager? It seems I didn't have to call ros::spinOnce() anywhere to get those to work, but I ended up having to call ros::spinOnce() every 100ms anyway to get the incoming pose commands to update.

spin/spinOnce/etc. only affect calling your callbacks. Publishing a message does not require spin/spinOnce at all. (Mentioned briefly in the pub/sub tutorial: http://www.ros.org/wiki/roscpp_tutorials/Tutorials/WritingPublisherSubscriber, and more in-depth in the callbacks/spinning overview: http://www.ros.org/wiki/roscpp/Overview/Callbacks%20and%20Spinning).

Josh