No. Georgia does not require gun registration, nor permits (other than permits to carry concealable arms) Link to a summary of Georgia gun laws: http://crime.about.com/od/gunlawsbystate/p/gunlaws_ga.htm
The 50 caliber pistol is the highest pistol which can be purchased without the need for a permit. Some pistol shotguns exist which can be 75 caliber weapons.
No
You will need the services of a good gunsmith.
No.
A person will need to go to the probate court to renew a weapons permit in the state of Georgia.
In MOST of the US, a permit is NOT required to purchase a .22 rifle. IF one is required in your area, it is because elected politicians passed a law that says you need a permit. You would need to ask them why they did that.
Yes
yes
We need the make of rifle.
Try e-gunparts.com
The SKS is not an assault rifle, nor even a BATFE-defined "civilian assault weapon". And no, a permit is not required.
No.