Glad to hear it's going well, Patrick.
That, and the blackout curtains, will make as much of a difference in contrast/blacks as the most exotic screen materials and a projector upgrade. See the effect, and use the filter or a grey screen if you need to further deepen the blacks.
He's not too bright. That's even less-informed than his screen suggestions. Power down from the remote, then turn off the switch after the bulb cools, about a minute (green light stops flashing). The settings will not be lost.
To make the image look well-integrated and not like a bunch of pixels through a screen door, it is best to sit approx. 2x the screen width with the 4805, as with any standard definition pj. I owned one of the first in the country, I've tried it.
Well, then, forget about the artifacts and...