I joined EAA on June 29 of this year but have yet to receive anything in the mail. Will this impede my ability to receive member-only Airventure discounts when it comes to admission, camping, etc.?

When I joined I opted not to order advance tickets or anything because I wasn't 100% sure what days I will be attending. At the moment I know for sure that it will be through Thursday and will start on either Sunday or Monday. If it's Monday, I will just pay for four days ($27 x 4). But if I'm going to be there five days (fingers crossed) I will pay the $115 week rate. My question is should I pay in advance or when I get there?

Now about camping. I was planning on spending three or four nights in Camp Scholler, but someone on here alerted me to alternatives that cost less and are MUCH closer to the main grounds entrance gates than I would otherwise be. But can I still use the Camp Scholler showers, etc, if I go this route? And if I do decide to camp in Camp Scholler, should I register in advance or when I get there?