took my FCG out to polish my trigger and I noticed some slight damage. Is this from rotating trigger pins or normal wear and tear?

Only the middle picture turned out well enough to use. It appears that you've lost a little finish, nothing more. Were the pins snug or really loose when you removed them? I prefer to set my lowers up with relatively tight pins, making sure the hammer and trigger rotate freely around them. Grease is your friend. I've noticed loose pinned rifles don't have as consistent a trigger pull as the tighter ones do. I wouldn't worry about it, but is you do, get some of JP Rifles or KN pins - .155" should do.