Another question.
In a lot of movies and other media, the lower ranks call the commanding sergeant "Sarge".
Is this acceptable, or disrespectful?
After Basic Training it's perfectly acceptable and not disrespectful. It would be like a sailor calling a Chief by "Chief" that is the rank. When I was in the National Guards the First Sergeant would call roll while we were in formation for the morning. Some would answer "here first sergeant or "Here Top". Actually the Sgt in charge of my work group I called by his last name usually. At Voc/Tech where we were students I called him by his first name. As long as no blatant disrespect occurred the enlisted ranks among each other weren't as formal.
While in the navy my Chief half the time I called "Whale". It wasn't disrespect and he knew it as did everybody else. He had made Chief {E-7} while running our shop as an E-6 and we had always called him by a nickname he had for most of his time in the Navy. He's the one who named me Dog. He was Gung Ho Navy Lifer but in a comical way. Duriung General Quarters {Battle Stations} he would sing Anchors Aweigh for the duration which usually lasted four hours. First time he did it to me I started barking and howling at him so he called me Dog. If we were in a situation where an officer was present I would call him Chief. But then again some of the officers called me Dog. That was on ship BTW where it's a bit less formal but you remember who's in charge.
When he made Chief we all were glad because he earned it. He sent me to a PX at a Naval Air Station in Italy when we hit port to buy his new uniforms. Chiefs wore Khakis. But by traditions of the chiefs {not Navy regs} he wasn't supposed to buy them till the day he actually made rank. I went and bought the uniforms for him on the quiet. If it had slipped out the other Chiefs would have made his initiation or hazing ceremony a torment LOL. Hazing was allowed back then for many things LOL :>}