The radio announcer gives the call letters at AM 520. In the U.S., AM stations are between 535 and 1700 (KHz).
When Root gives Fusco his 'exit plan' documents, there's a Maryland Driver's License for his son included. It shows that he is 11 years old, and got his license at age 10. (and 5'5" tall, weighing only 75lbs...)
Each time Finch opens the Faraday cage he would be allowing EM signals out. Instead he should have an airlock-style setup; a Faraday cage within a Faraday cage.