I think there is a day around the first of July when you can choose seats based on what is available. I use two of my grandparents tickets, so I just sit there. Probably going to have to do the same thing as you though in the near future.
How the seating chart works or how the points system works? I'm confused? Are you looking to go through the Gamecock Club for your tickets or are you looking to buy an upper deck General Admission package if they become available?
I depends solely on your level of giving and your total points accrued. That is all it is based upon, nothing else, and it is so controlled by a computer ranking system these days that not even Harry Pastides could go in the system and upgrade you unless you've got the points to be moved/upgraded.
You'll just have to do your time. There are some good seats coming open each year so things are fairly flexible. I was told five years at Silver Spur will get you decent tickets these days.