In most U.S. states, yes.
Yes, you can buy a gun case for anyone.
Depends on where you are. In MOST of the US, there is no requirement to have a permit to buy a gun. You must be an adult and pass a background check.
No
Other than a toy gun or water gun, the next most powerful one a citizen can have without a permit is a "B.B. gun".
No.
No
You can't carry a gun in Georgia without a permit.
It depends on where you are. In the U.S. you can own a gun in any state without a permit, except that the state of Illinois requires an ID to purchase a gun.
Not legally. Florida requires a permit to carry a gun on your person in public.
You don't need a permit to buy a gun in Oklahoma, if you mean concealed carry permit I think it depends on what crime you are wanted for.
The magazine (clip) is not a gun, and is only parts. They may be purchased on line or in stores without a permit. DO be aware that some magazines are restricted by STATE laws due to size, and may not be available for sale to your state.
No, not in public. You can carry a gun in your vehicle in Mississippi, but not in public without a permit.