The only time you'll ever be allowed to do this is the first time you get a marksmanship badge awarded when you're at Basic Combat Training. At the end of the qualification range, you'll take it off, and never wear it on your ACUs again.
No, you cannot.
Until you requalify with a weapon with a different proficiency level (expert or sharpshooter)
No, you cannot. The Parachutist badge is a Group 4 award, and has a higher level of precedence than Group 5 awards such as the Driver and Mechanic badge. Thus, it will always be worn above the Driver and Mechanic Badge.
It's not sewn, it's pinned on.
$5 see ebay
You wear a blazer badge when you have received an award that allows you to wear the badge. Also, you wear a badge when you belong to an organization that requires you to wear one.
$10 try ebay
ACU'S and some units are starting to get multicam
They wear the same uniforms as the rest of their unit. This may be the ACU or MultiCam uniform for the Army, the MARPAT uniform for the Marines, the ABU for the Air Force.... special operations units have a bit more leniency in what they wear as far as uniforms go. They might wear any of the above, or even the phased out BDU, DCU, or ERDL uniforms if they saw fit to.
No, you only wear one Category I badge.
No, although it might be overlooked in a field environment.
Yes they do! The dogs wear the badge around their neck