I am trying to do the same kind of thing using the same kind of method than the one from "augmented engineering" or "byo3D" (origial project of augmented engineering I guess). This means calibrating the projector with the Kinect RGB camera. Then you can do all what you suggested more accuratly. Just render the point cloud or mesh from the Kinect from the viewpoint of the projector using its projection matrix you calibrated... I didn't understand fully the Padé transformation but I'll have a look, but the OpenCV calibration seems to me as a safe and easy way to do the calibration. Good luck and keep me updated on your progress.

Right now the other challenge is that because of how Cinder-Kinect maps the depth values to greyscale, there's no way to reconstruct the depth params with high accuracy (see http://forum.libcinder.org/#topic/23286000000453029 ). That will probably be a necessary component of this type of work.

Regarding the depth problem with Cinder-Kinect, you might want to consider using OpenNI as it use firmware information to translate depthmap into real world info and is not dependant of the hardcoded calibration done on another kinect... Also you have a wonderful function to directly distord your depthmap to fit your rgb image and thus you don't need to calibrate the transformation between those two.