Hey Nathan, that's some excellent background, explanation, and synthesis. Thanks. I'll work through your work here throughout the day.
Last night, after we connected, I followed that video walk-through until I reached a step that required a lot of processing (the final Photosynth Toolkit step). That step requires using PMVS2, and I think it failed for me. I am not sure that I started it up correctly or "aimed it" at the right files. Steps 1-3 of the Photosynth Toolkit are workable, assuming one has the video you linked to me previously and which I link to above.
Once again: Josh Harle's video is clutch
Anyhow, great write-up, I just stepped in from a morning of X-country skiing, so you've given me a lot to consider. I recognize the system-related limitations of Photosynth all too well. Darn limits! 192 Gb of RAM!!!!!! Yowza! But on the other hand, I suppose we do have a demand...