The exposed outer lens is glass, underneath the lens is plastic.
The 160 degree or 200 degree is personal preference. The 160° has a more narrow view while the 200° has a much wider view. Be advised that a slightly larger hole is required for the 200°. Drill a 1/2 inch hole for the 160°, and a 5/8 inch hole for the 200°.
You will start drilling the hole with a 1/8" drill bit and complete drilling with a 1/2" bit.
To start the hole, you need to use a 1/8" drill bit. You need to use a 1/2" drill bit for the finished size.
Yes it can you drill through the fiberglass just like you would a wood door
Could be glass since the view is so clear.