Some fairly good answers for number 1 and 2, although for number 2, an important thing to know is that Synthetics cannot and in RP, don't know how to operate firearms. They could probably recommend holding techniques or maintenance, but cannot mentor for actually firing them as that'd make no sense, if you catch my drift.
Another question: If you were asked by a marine to help you with operating their firearm ICly, what would you do?