Thanks for all the advice, guys. Yeah Ian, if I had it to do over again, I would probably actually project the image onto the guy and capture the whole thing live. But, at the time, there were too many inherent timing problems to capture it live. Plus, I would also have the added headache of getting slides made (remember, it should look like a slide projector, not a video projector).
I didn’t care so much about the displacement of the image on his body, as I just blurred it very slightly. The soft light xfer mode gave me some desired results, but even with opacity on this layer set to 10%-20%, I was getting to many unwanted problems with how it interacted with the keyed layer. I tried adding an alpha matte in addition to the soft light, but it just got stranger…