What kind of ammo? Sometimes the really cheap stuff is kind of spotty. Are the firing pin strikes solid looking on your ammo? Are they all the same or are some "lighter looking" than others? How many other types/brands of ammo have you tried in it? When you tore it apart, how grungy was it? Could that have been a contributing factor?
IMHO, (I'm not a gunsmith) I wouldn't sharpen the firing pin.
I would give Ruger a call before you get to "improving things." YMMV of course.
If all else failed I didn't wish for Ruger's CS to save the day, I would probably CAREFULLY, A LITTLE BIT AT A TIME, file away some of the yellow marked section.
NOTE: Too much is bad too. You don't want it hitting the breech face.
But I would at the same time, have a new firing pin on it's way, just in case things went awry.