Looking a little closer at your photos there are a couple of other things you might want to check.
Your rear brake adjuster lock nut seems to have come loose and it looks like your rear sprocket holder has some shiny spots on the inside of it on the posts that the bolts thread into. That usually means that either the axle carrier came loose at some point and started rubbing on the swingarm, or your axle bearings are shot and it's causing the axle to pull against The swing arm. You'll be able to tell for sure by looking at the swingarm for any gouges. If in fact the sprocket carrier has been rubbing against the swingarm you need to take a good look at it and make sure that it isn't cracked. I don't think by the slight amount of rubbing that I think I can see that you would have damaged the swingarm yet.