>>First off, don’t put any lights between the projector and the screen. After all, a projector is sending a beam of light to be reflected back at you, and any lights between it and the screen will only degrade what you see on the screen.
I don't know if this is entirely correct. I cannot see any reason why putting light through other light will hinder the light of each path.
The only thing that will effect the image on the screen is if you have light hitting the screen and washing out the image.
I think if you can have complete darkness on and around the screen you can have lights in the path from the projector to the screen.
I just don't see how other lights in the path of one light will effect its penetration.
