Yes.
No, the Army Commander's Award for Civilian Service ribbon is awarded by the U.S. Army and is not authorized for wear on Marine uniforms. Each branch of the military has its own set of authorized ribbons and medals.
Not in uniform, no. Even in civilian clothes, you're bound to get reamed for it.
If you're taking a civilian flight you booked on your own, the airline isn't going to prevent you from doing so. However, you're not supposed to - when you're traveling, you're supposed to be either in Class A/B uniform, or in civilian clothes. If you're taking a DOD chartered flight to a duty station (for example, if you're assigned to a unit in Korea, you'll take a chartered flight to Korea), you absolutely do not want to do this - again, Class A/B uniform, or civilian attire. If you show up at your Replacement unit in PTs, you're going to get hemmed up for it. If you're on a military or charter flight to a combat zone, training deployment, etc., you're going to fly out in ACUs (it was BDUs and DCUs during my time). That's another uniform you're not supposed to wear while traveling. In short, when traveling, unless otherwise specified, it's Class A uniform, Class B uniform, or civilian attire. You're best to go with (appropriate) civilian attire.
No. If it's not actually a component of the uniform, it's not to be worn with the uniform.
for now.
On social occasions when the prescribed uniform is the Army Blue Uniform, personnel who don't have one are authorized to wear the Army Green Uniform with white shirt and bow tie.
Amongst the junior ranks, that's the tradition.
a sausage buddy (sausage making grinder/machine)
The combat action badge are worn with "Class A" Army green, blue or white uniform coats. You must wear that uniform when wearing the badge.
I went through Basic in 98, and the Class A uniform was the current Army Green uniform, which is in the process of being phased out. At that time, everyone was issued Class A and B uniforms. A lot has changed in the 12 years since, but that's one which isn't likely to, and you should still be issued the current Army Service Uniform (which replaced the Class A/Army Green uniform). Upon graduation, you would be wearing that uniform for the graduation ceremony, and thus would have to have one issued to you. Special uniforms, such as Mess Dress, however, will have to be purchased on your own, if you wish/need to have them.
Yes. It is an Army uniform. Active, Reserve and Guard comform to uniform policy.
They enforce the UCMJ (the Uniform Code of Military Justice), the same as uniformed military members of the military police.