Tonight I tapped an M2 hole in acrylic to see how the threads would hold up. I was able to tighten the screw enough to strip it completely and the threads did not budge. After removing the screw (from the other side with pliers), I was able to use a new screw in the hole as if nothing had happened.
I have to admit, I was not expecting this to hold up nearly as well as it has. I was fully expecting to have this fail dramatically. This is a really promising result because it simplifies the acrylic version of this case dramatically. The threaded inserts were a total PITA, so if I don't have to use them, that is awesome. The threaded inserts were hard to find (in M2) and they were not cheap, so that is a huge bonus.
The tap was $7 on ebay (I already had a handle that works), so that is a pretty good investment. This is how I planned to do Aluminum and Steel anyway, so its nice that I can just use the same process...
Now I need to see how thin I can go with the acrylic before the threads become a problem. I don't think it is realistic to do the acrylic less than 1/8" anyway, so I actually expect this to work pretty well. This test was with 5mm acrylic (just over 3/16").
Here is a pic...