Getting a bit a wear on the mast from one of the cams, can I just paint on some epoxy now and then to protect it? Don't really won't to wrap it as it's not that bad yet and don't won't a bulge as the glass would be thicker then the dent.

I think epoxy only would crack and detach quickly, you can get very fine cloth that will add minimal thickness

Mast wear from cams aids rotation

Painting some resin on the wear points is fine. I don't have cammed sail but I do my my mast tips. Will prolong their life.

Any thoughts on using the same clearcoats the factories use? Is that polyurethane clearcoat?

Just paint on a thin layer of epoxy resin. It works well for cam wear and mast tip. It doesn't crack or wear off easily.

Just painted on some epoxy, if that doesn't work I've got some carbon cloth I'll try next.

Check the cam too, maybe some grime got stuck on it.
Ezzy top cap puts sideways pressure on the mast, I rotate the mast to even out the wear but ultimately need to add a layer of cloth too.

carbon doesn't wear well, you'd be better of with glass.