I always have sent my firearms needing repair through an FFL (Cherokee Gun & Pawn) and sent back to to them for pick-up. Since I have purchased a few things from them in the recent past, CGP did it with no fee. (several times.) I like being legal, and I like CGP's fantastic customer service.
From page 7 of the website you referred to:
Anyone who can legally own a firearm can carry it loaded if contained in a closed Glove Box, Console, Trunk or a vehicle without a trunk in the Luggage Area in a container secured with fasteners. Their law is very specific on the only locations where...
Possibly, but SC still does not allow carry of any kind for Georgia residents. They do not recognize permits from States that do not require a gun safety course to get a permit.