That's cool. If you're not concerned about it looking factory and you like the way they fit with out the welting, I would do as you stated before and apply the rubberized coating to smooth the rough edges.
If you plan to paint over it, just make sure it will accept paint. You may even be able to find it in a color that matches well so you don't have to paint over it. I know it comes in black so if you're going with black paint, you should be fine either way, painted or bare. I don't believe it will have a gloss finish to it. It's more of a satin I think.