I was thinking about trying to become an NCO. How would that work out for an ENTP?
NCO doesn't mean a whole lot to be honest with you. I was an E-5 in the Navy, which is a Second Class Petty Officer (NCO). All that really means is that I am senior to anyone who is E-1 through E-4. Anyone E-6 or above was senior to me. I think E-4's through E-9's in the enlisted ranks are deemed NCO's. So, E-1 through E-3 are the only people who are not NCO's (I think is how it works in most/all branches). So, as an E-5 I was just in the "middle" of the enlisted ranks. Here's a breakdown of how it seemed to work in the Navy (most other branches should be similar):
E-1: Total noob. (Title: Airman or Seaman Recruit) (<2 years in the military)
E-2: (Airman or Seaman Apprentice). You've gained a little bit of experience or got meritoriously promoted (<2 years)
E-3: (Airman or Seaman). You're like a "senior grunt". You're still a grunt, but you may be tasked with showing the E-1/E-2's the ropes. (~1-4 years)
E-4: NCO. (3rd Class Petty Officer). You're now expected to show/learn a bit of leadership skills. You're still going to be working "hands on" with the E-1 to E-3's, but you might be something like a "team leader", for lack of a better term (1-10 years)
E-5: (2nd Class Petty Officer). In the Navy, this was basically a shop supervisor or assistant shop super. So, let's say you work in the parachute shop. You'll probably be the shop lead on the 2nd shift (night shift) - you'd be running your office/shop either at night or in the absence of the E-6 shop supervisor (2-20 years)
E-6: (1st Class Petty Officer). Shop supervisor. You would be in charge of the parachute shop for a squadron, for instance. Some shops had 6 guys, some other shops (like the mechanic shop, hydraulic shop, airframe shop, etc.) had like 15 guys (5-20+ years)
E-7: Chief Petty Officer. In the Navy, this is where you change uniforms - you're now a Chief Petty Officer (still NCO). So, as an E-7 you would oversee a few different shops. The E-6 supervisors would report to you. You're also expected to be extremely knowledgeable at your particular job. If anything goes wrong or if the E-5's/6's can't figure things out, you had better know the answer at this level. (8-20+ years)
E-8: Senior Chief Petty Officer. These guys are very senior within the enlisted ranks. Very, very knowledgeable and very well respected. (15-20+ years).
E-9: Master Chief Petty Officer. The senior most people in the enlisted ranks. They are basically running/overseeing the operations of an entire aircraft squadron. They report to the officers (Commanding Officer/Executive Officer, etc.) on the technical aspects of what is going on. (20+ years).
Now, maybe by NCO you meant that you wanted to start enlisted and transfer to the officer ranks? It's very rare for this to happen, but every year they allow applications and a few select individuals are selected to move to the officer ranks. For instance, a good friend of mine just recently moved from E-7 to O-1 in the Navy. He's now a commissioned officer. He never became an E-8 or E-9. Again, this is extremely rare - this guy was an E-6 with the Blue Angels and he wants to be a congressman one day. He's ENTJ and he's extremely dedicated and motivated...and they recognized it and rewarded him. I think E-5's and higher are eligible to apply for this, but if your performance evaluations are less than perfect you basically have no chance. Since he's already 14 years into his career, the highest he'll probably go is O-3 or O-4 (if he stays in for 25-30 years). These guys have mucho respect because they worked their way through the enlisted ranks - so they have the technical knowledge of everyone else (they were once grunts), but now they are running stuff.
So, you have E-1 through E-9 in the enlisted ranks. And O-1 through O-10 in the officer ranks. The old guys you see giving press briefings from the Pentagon are basically O-6 and above. In between the E's and the O's, you have "Warrant Officers". These guys are also former enlisted who have applied to be promoted to the officer ranks. There is WO-1 through WO-5. They are officers as well, but they are sort of more "technical" officers. Still expected to be involved in the "technical things" of the enlisted ranks, even though they are officers.
So, in my squadron, E-1's through E-3's did all the grunt work on the jets (repairs, inspections, heavy lifting, etc.). E-4's and E-5's led the work and performed some of the more complex stuff. E-6's basically supervised and was the resident expert.
So while NCO's are expected to know what they are doing and expected to take on some leadership roles (especially in times of conflict), you're still VERY much in the highly structured, daily grind of military life.