Hrm. Well, I'll say what I know. My brother is in the process of applying for a Class III license, but neither of us have concealed carry permits (we mostly just do range shooting.)
First off, full auto is just plain illegal, even with a class III. Silencers are fine if you jump through the federal hoops.
Concealed Carry is shall-issue; i believe there's a training course involved but I'm not sure. ( a good source for info would probably be http://www.scfirearms.org/ ). At any rate, it's easy enough to get that I've seen gun shops advertise "get your CCW here" programs. Once I buy/find a pistol that I actually wouldn't mind carrying I'll probably get the permit, just to have it.
Gun use for home defense isn't just legal, it's openly encouraged by the state attorney's office as crime deterrent. (even to the use of such slogans as "invade a home, invite a bullet.")
Apart from that I'm fairly vague as to the specific laws. I have a sneaky feeling that it's not kosher to do open carry (especially in cars) but I think that if you were charged for that it would more likely be on some sort of "disturbing the peace" charge than it would on express violation of a gun law. All in all, I'm fairly happy with SC's gun laws - they could use work, but on a national scale it's a good place for gun owners to be.