Ok. I do polish and wax the cowling on my 75 hp Merc. It is new, and I like it shiny.
I have painted them, but beware, the price of the replacement stickers might shock you. Hence, sticker shock.
You could also use a little touch-up paint to cover scratches. Truly, we learn to live with some imperfection, but I am one who likes to have a really nice looking boat. Of course, I take care that it operates well too.