I'm not sure about the numbered stars, but the first one, with the "C" in the middle means that you are a CHARTER MEMBER, and got on board at the beginning of this grand adventure.
The next one says "Star Member" when you hover your mouse over it. I think that just means that you are paid up for this year???
The next 3 on your profile show that you paid for Series 1, 2 & 3 when you hover your mouse over it.
I'm not sure what the other numbers designate, but assume it's a series?