The question answers itself. If you are a convicted felon you cannot legally own a gun. Also, if you have been convicted of domestic violence, even if it is a misdemeanor, you cannot legally own a gun. You gave that right up when the crime was committed.
I'm not sure specifically about South Carolina, but if the conviction was some sort of felony, federal law prohibits you from purchasing a firearm.
No money, no gun shop nearby, felony conviction, underage
Yes, if you were convicted of it. It's a felony charge.
That all depends on the nature of the felony, and how long ago. IF the felony was a crime of domestic violence, then FEDERAL law prohibits you from ever possessing a firearm. If it was a violent felony or a felony involving a firearm in the past 20 years, no. Start by hiring an attorney- you will need one.
No! Actually, that depends on where you are and what the charge is. In the U.S. any felony will prevent you from buying a gun legally, but misdemeanors do not, except for misdemeanors of domestic violence.
IIRC, a DUI felony is a state, and not federal felony. At the moment, no - federal law prohibits anyone with a felony record from purchasing, possessing, or having access to a firearm. However, if you get yourself an attorney, it MIGHT be possible for you to have your firearms rights restored, provided it's a felony only at state, and not federal level. Bear in mind, though, that nothing is guaranteed.
Felony
You will have to contact a lawyer. To many variables and you don't state if it was a felony conviction or not.
The senetence would be up to the judge, but KNOWLINGLY buying a firearm for someone that has been convicted of a felony is a serious crime- and a sentence of 5-10 years in prison would not be unusual.
Find a lawyer who is familiar with firearms law and consult with him/her.
Yes it is a felony.
No.