Thanks for the nice comments, I am super happy with the project so far.
Regarding the attachment of the screen material to the slot in the motorized shade roller, I just wedged hollow rubber pipe strips into the slot with the fabric. I crammed one in ever couple of inches. They would deform enough to squeeze into the slot and pinch the screen material in place. Individually they were not very strong, but a 16' row of them seemed to hold fine. Also, when the screen is fully deployed, it is still wrapped around the shade tube once or twice, so the downward forces makes the screen tighten on itself and not the rubber pieces wedged in the slot.
I really like your projector A/V setup, that is my next project, building something similar. I really need to get better sound.
I would love to attach my projector under my porch and run all the wiring through the ceiling, but I think the AZ sun/heat and monsoon rain in the summer would destroy it. I looked into projector enclosures, but they are super expensive.
So far the BOC has been fine and doesn't stick to itself, but we haven't had any real heat yet.