Ignore code 12, it'* system normal.
I don't have 11 on my list.
21 tps sensor out of range
22 tps sensor signal voltage low
23 intake air temp sensor out of range, low
31 cam position sensor fault
All kind of unrelated. I would start checking all the wires for damage. I would also inspect the TPS, something could be wrong with it.
As for the hard brake. Check the vacuum line to the brake booster. If that'* off or collapsed you will loose the brake assist, and it will be hard.