It depends on the duties.MOS is rank specific only in the last several characters. MOS is always job specific.
Same as it is in the entire Army - Military Occupational Specialty, i.e., your job function in the military.
There isn't one. First Sergeant isn't an MOS - you don't enlist as a First Sergeant. It's a rank and position which is achieved through time and experience. It doesn't change the holder's MOS - if they were, say, 68 series, 88 series, 11 series, etc., they would retain that CMF identifier. What does change is that, when one is promoted to E8, they're no longer considered specific to a certain MOS, but rather, a generalist in the entire field. So, if someone were 68W (Healthcare Specialist) and were promoted to E8, they would no longer be 68W, but rather, 68Z, making them a generalist in the entire Career Management Field.
MOS 76Y is Unit Supply Specialist. Rank is Staff Sergeant (E-6). No special qualifications.
11B is for Infantry. 30 is for skill level of Staff Sergeant (E-6). G is an Additional Skill Identifier (ASI) meaning Ranger qualified. You probably would not want to mess with a soldier with MOS 11B30G.
Any MOS filled by a commissioned officer or Warrant Officer. Perhaps if you took up an occupation in Finance or some other REMF MOS, you might do without it, but there's still going to be some sort of instruction which goes along with those MOS - if not specifically Sergeant's Time, it'll likely be some sort of classroom instruction. Certain jobs may get you away from Sergeant's Time training, even if the MOS doesn't. For example, when I was at Fort Drum, the bus drivers on post were 88M (Motor Transport), but weren't assigned to the same units (FSB/CSB.MSB) which operated five ton trucks, etc. Their work schedule not only got them put on separate rats, but probably also made Sergeant's Time training a bit unlikely for them.
0341 is the United States Marine Corps MOS for a mortarman, ranks Private through Sergeant. The US Army equivalent would be 11C (11C1 for Private through Specialist, 11C2 for Sergeant).
The '3' indicates skill level 3, which would be the rank of Staff Sergeant. A Staff Sergeant would be a squad leader, or a Staff Sergeant with seniority or who is close to promotion to Sergeant First Class might fill the role of Platoon Sergeant. They might also work as a staff NCO in a battalion/brigade/division/etc. shop, which wouldn't be a leadership position.
Really depends on MOS (occupation), turnover of that occupation, etc. Typically, after ten years, most personnel hold the rank of Staff Sergeant, and a fair number will hold the rank of Sergeant First Class.
Pass the AFPT, qualify on the range, attend all drills, attend NCO school and take courses pertaining to your MOS.
A Sergeant Major in the Special Forces usually holds the MOS of 18Z or Special Forces Team Sergeant. They are usually the most senior enlisted member of the team, or ODA. They help oversee the training and proficiency of the team when they are home, and prepare them for deployment. They also help plan and organize interagency or multinational operations.
This one doesn't make sense. MOS 37F is a Psychological Warfare Specialist. Rank is Staff Sergeant (E6). His special skill is "Special Operations Support," which makes sense here because these guys belong to United States Army Special Operations Command. SQI S outranks SQI P, but this troop is also airborne qualified. The Additional Skill Identifier H8 means "wheeled vehicle recovery." The only people who can carry that ASI are mechanics--63B (light wheeled vehicle mechanic) and 63S (heavy wheeled vehicle mechanic). It's very possible that the sergeant could have gone to this course; the Army allows people in overstrength MOS to reenlist for a different job, so this sergeant could have been a mechanic who took the wheeled vehicle recovery course just after he graduated from AIT, then reenlisted for PSYOPS. In this case, the sergeant's primary MOS would be 37F3S, and his secondary MOS would be (probably) 63B3SH8. This man is the most popular staff sergeant in his unit, because every time someone drives into one of those Humvee-swallowing holes that every drop zone in the Army has, this sergeant will be the one dispatched to fish him out.
14 to 16 years. It depends on the MOS (Military Occupation Specialty) and those who are retiring. When someone retires in a MOS it creates a vacancy and openings for promotion. In some MOS's it can be fast and others very long. When a opening takes place (someone retires) then the Marine Corps promotion board looks at the available candidates and their fitness report scores to fill the vacancy. So make sure you have excellent scores and reports. I picked up SSgt (E6) in 10 years. Gunnery Sergeant (E7) may take up to 14 to 16 years.
The 73C MOS no longer exists. From 2001 - 2004, the US Army underwent a major reorganisation process which resorted a lot of the occupational specialties. Prior to this reorganisation, 73C was the MOS for Finance Specialist. The "2" indicates a skill level; in this case, a Sergeant, while the "O" indicates that they possess(ed) no other skill/qualification identifiers (such as parachute qualification, instructor certification, etc.).