No codes, and the feel has not changed since I have had the car. Upgrading the brakes got rid of the shakes and did have a noticeable effect on higher speed braking, but the initial bite and the overall feel is/was the same.
I will check those things. I assume item 2 and both in item 4 from that diagram. I feel better about it not being the lines as I looked at the type of lines used, and they are quality lines that pass salt spray testing that any 2011 model should not show signs of rust through symptoms.
If it is the master cylinder, should I just upgrade to the 2013+? Are they direct replacements? Also, if I am in there should I do the brake booster to 2013+ as well? Direct replacement? On Rock Auto, I am only out ~$150 for both.