Looks like a good Beginner project with a high degree of completed parts.

As for covering, I would master a system on some simple test frames, get real good confidence in the process before going to cover the airplane.

As for the fuel selector question keep all critical items like fuel selectors in your forward field of view and easy to see & reach location, Use Aluminum lines & AN "B" nuts for the routing and connections from the tanks to the carb.

Hope this Helps,

Spencer

Tech Counselor Composites & FWF