Would an E9 comply if ordered to attention by an O1?

As an E4 SF, our former chief, at the time our Command Chief, was ordered by a 2LT to salute him while assisting at base entry...Command CMSGT says, "I've had these stripes longer than you've been in the Air Force"....guess who drove off, tail tucked between their legs? Lol

From what Ive seen, back at my AIT at Ft Gordon, it wasnt really with an E9 and a 2lt, but it was an officer and the senior NCO, if anything after the NCO saluted and everything, the officer was the one standing in parade rest while talking with the NCO.
So yes, even though it is under the oath of enlistment, an NCO should render a salute to an officer no matter what, but in the end, the NCO (whether its an E-5 or E-9) has more experience than a new officer (who only got commissioned through the cadet program, or ROTC, or any officer school) and that officer should still respect the NCO.

Yes, he would be required to, but it would be under protest most likely if they were arguing

Of course the E9 would be required to obey the order. No one id bound to obey any illegal order but a Second Lieutenant ordering Sergeant Major to attention is not an illegal order. Commissioned officers are commissioned by the Congress while Noncommissioned officers are promoted by the respective branches of service to serve in positions of authority over other enlisted members of lower grades only. Noncommissioned officers have no law enforcement over subordinates whereas commissioned offers do have such authority.

it depends on the Situation. I have chewed on a couple of Lt´s necks and set them straight as an E-7. The bars on the shoulders are there to learn from their Senior NCO´s. I guess I pissed off a couple of officers because I operarted as a Platoon Sergeant for 10 years without a Platoon Leader.

He should. I once saw a master chief GM choke the shit out of a lieutenant jg

It would be set day for the Lt

yes

Yes, as a young specialist at Ft. Ord, CA, a young O1 jumped on my battalion CSM and a group of 1SG. That evening, I was on staff duty at the battalion hq and the battalion commander called the young 01 into his office and ate him alive.

2lt would lose