From highest to lowest: General of the Army (5stars), General (4stars), Lieutenant General (3stars), Major General (2stars), Brigadier General (1star), Colonel,Lieutenant Colonel, Major, Captain, 1st Lieutenant, 2nd Lieutenant, Warrant Officer 5, Warrant Officer 4, Warrant Officer 3, Warrant Officer 2, Warrant Officer 1.

He was the highest ranking officer captured..Yes

No. Major is one of the Field Grade Officer Ranks, while General is a General Officer Rank. You may be thinking of a Major General, which is one of the General Officer ranks, but is still much different from a Major.

Not necessarily - it is different duties.

On the left, so that the general can return salutes.