I bought this road bike as my first road bike in 2011. I have not changed the chain or any parts on it since then and I bike on it almost daily. It's been running great, but sometimes I have trouble changing gears and I feel like the issues are getting more frequent. I had a major accident on this bike in 2012 learning how to use the clipless pedals but the bike landed on the opposite side of the cassette.
Are the scratches in the picture below "normal" for a bike this old? Do I have to replace any parts? Is it safe to ride as-is?
Here are some pictures: