Frame art
 

Is there any kind of paint, or pen I can use that is permanent and looks nice for a frame?

Also, if I have something in permanent marker on my frame, that I'd like very much to protect and keep on there. How should I protect it? Only thing that came to mind for me was a layer of epoxy over it. What kind of epoxy if this is a good idea? Can I sand and smooth over epoxy?

epoxy? might have better luck with a clear coat spray paint from the automotive or hardware store.
Automotive touch up/fixing spray paint is pretty good IMO if you aren't looking to spend too much.