Is it a 3/32" Chain or 1/8th?

The teeth of the cog as you rotate should protrude dead center between the links in a perfect world. If the teeth are comming up and scraping the sides of the links then your chain line is definitely a problem. A 1/8th chain will give you a little more room for play if you are running 3/32 cog and chainring.

One more point on the loose ring bolts is that as you cruise forward you may be shifting everything out of wack and then when you slow down you are reversing the stress and putting things back where they belong.

Next could be bad brrings

If you have a bad chain line I suggest using a brake