Quick grammar question

So I'm writing Stargate, and there's a lot of military people, which involves a lot of military forms of address, and I can't seem to keep it consistent. I tried searching google, but I keep getting conflicting answers. So, how does the rules of capitalization work?

Eg.
"Reporting for duty, sir!" said the cadet. - is the "sir" supposed to be capitalized?

"He's reporting for duty, General," said the aide. - is the "General" part supposed to be capitalized?

"Did the colonel say we could shoot?" said the guard. - I'm guessing the "colonel" in this case is not capitalized, right?