A) You're assuming that you'd be given a trial by jury, rather than branded a traitor (aiding the enemy) and either kept in guantanamo or tried in a secret court. They would hold you up as an example - head on pike, as it were - to all others who might dare to expose their illegal actions. If you look at the history of civil rights leaders, you'll find that Rosa Parks wasn't just some random hero who stood up for herself one day; she volunteered and was chosen by community leaders to be a test case. They picked their timing, circumstances, and people very carefully - both from a legal and a public-relations standpoint. Whistleblowers have no such luxury; they find incriminating information and are immediately presented with an ethical quandary and the necessity to act.
B) Why are you lambasting someone for not wanting to go to prison and face "enhanced interrogation methods"? He discharged his ethical duty by telling us what he found. He doesn't owe us a damned thing more.