I do this kind of work day in and day out 6 plus days a week. I would never put any type of varnish, floor wax, or poli-glow on anything. I have seen the damage done by this type of process. The realty of owning anything gel-coat is that it will oxidize and the only way to keep it looking good is to maintain its shell at least twice a year.
Before any protection goes onto a gel-coat finish, you have to remove the oxidation. After washing the RV, we use a wool pad and a rotary polisher w/Presta Super Cut Compound. We then do a second pass with a Positive or direct drive Dual Action Polisher with a Orange Light Cutting Foam Pad w/Meguiars Flagship Premium Cleaner Wax.
This combination ensures a beautiful finish. After that all you need to do is wash your RV every 3 to 4 months, and wax it with a preferred wax/sealant formulated for Gel-Coat. Future follow ups (waxing) can be done with Pro-Polish from Yacht-Brite (wax on/wax off).
Obviously you'll need to go around the graphics by hand. On the graphics we use 303 Aerospace Protectant.