How similar/different are the roles performed by Military and Civil pilots?
The biggest difference is that most everything in commercial aviation is considered administrative in the military.  The tactical employment of our aircraft, the non-administrative portions of flight, is what separates military sorties from commercial flights.  This emphasis on tactical flying has also led to significantly different cultures between commercial and military aviation.  There isn't a commercial pilot I would stand a chance against in a game of FAR/AIM trivia, but I also doubt they'd fare much better if the tables were turned and the questions were related to carrier operations.  We are two separate organizations with two unique mindsets to flying.