Jim, you are right on sanding to make plexiglass frosted. I had a birdhouse with a plexiglass roof. During the winter the sun would reflect off it and drive us crazy. I took 220 grit to it and it looks great and no more reflections.
As for other works, I have done some. I used FDUR#3 blades. At first it melted, but I put a layer of packing tape over the pattern and stacked 3 or 4 1/8" pieces with no melting at all. I like to soften the edges and have sanded them. You can also use a torch and do a quick pass over the edges to soften them. By soften I mean make them smoother. Sorry, no pics.