I have this same problem, I am bringing work ID card as I don't have passport/driving licence. Also something with my signature. Every year I have been up to register I have never been asked for photo ID. Maybe this year!!
Moisturise your feet every evening...it really helps. I swear by this! I have always suffered with blisters, it's just one of those things that comes with long distance running. I get through shed loads of Compeed every year!! They are very good!