No, you cannot.
Yes. If you have earned the Combat Action Badge (CAB) you can wear it on your Class A uniform.
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.
AR 670-1
The location is as shown on the chart at the related link below.
Combat Action Badge was created on 2005-05-02.
No. It's not transferable. You MIGHT be able to fill out some paperwork and have the Navy Combat Action Ribbon awarded as an equivalent (which can be worn on a CG uniform), however.
No, you only wear one Category I badge.
Medics cannot receive CABs (Combat Action Badge). Instead, they receive the CMB (Combat Medical Badge) for treating wounded soldiers in a combat situation.
If he's under fire, yes. The Army has a special case: if a medic assigned to an infantry unit treats a patient under enemy action, he will receive the Combat Medical Badge rather than the Combat Action Badge. Medics in non-infantry units will receive the Combat Action Badge.
On the left breast pocket on the left marksman badge goes on the right
According to the current AR 670-1, (Feb 3rd, 2005 w/ Summary of Change) on pg 298, you wear the CAB, (Combat Action Badge) 1/4 inch above your ribbons, centered, or if the lapel covers your badge, you wear the CAB so the left edge is aligned to the left edge of the ribbons.
Anyone who is fired upon and/or returns fire. Specifically, as the citation reads, 'engages or is engaged by the enemy.' Those eligible for the Combat Infantry Badge or the Combat Medical Badge are ineligible.