as far as the first question goes i have not done it but i believe they are running the fiberglass around the front of the firewall kind of like a limmiter strap incase the glue lets loose. I dont think it neccecary in most cases. but never hurts to have a little extra support if you want to do it. the second question there is a couple ways you can do this one is by putting some epoxy down 30 min then pressing the mat down on top then come back with some more epoxy and smooth it all out. the second is to glue the mat down with a adhesive I ussually use the stuff in the aresol can from the hardware store. then smooth the mat and push the epoxy in from the top getting it flat and smooth as possible. i have better luck with second option. oh ya i just use a scrp thin piece of wood about 2 to 3 inches wide to smooth and spread epoxy happy building and flying