This is a picture of one of the scuffs on  the limb of the ben pearson javelina i just got in a trade. it looks like it is just the finish scraped off. can it be repaired or should i just leave it alone?

As close as that spot is to your site window I suspect the limb is not bending much if at all where that scuff is.  
Either way, lightly sand until it is all smoothed out there and finish with a rattle can of Helmsman Spar Urethane.
If the whole bow is in need of a spruce up then lightly sand the bow, but not as much as this area, than spray the finish on.  
It's an easy fix and you will enjoy the bow for many years.

Right on. I'd suggest the whole bow. While sanding with fine grit, maybe 240 to start pay attention to be sure they are no small splinters raised. If there are any sand smooth and see with CA glue.