Welcome to the EGGhead Forum - a great place to visit and packed with tips and EGGspert advice! You can also join the conversation and get more information and amazing kamado recipes by following Big Green Egg at:
Congratulations and welcome! You are going to have a great time with your new egg. All aforementioned warnings about wallet draining are true.
Regarding your gasket, BGE does suggest that you keep the first few cooks rather low to season the gasket. But your gasket will eventually fail, when that happens contact the site gasket guru - @RRP. He will hook you up with a replacement gasket.
Get a good instant read thermometer, cook to temp rather than time, try something new every few cooks and have fun.
I did 50 lbs of pork butt for my son's HS graduation party. I also have an XL and did it in 2 batches over the 2 weekends before the party. After each batch we pulled the pork and sealed it in Foodsaver bags and froze it. The day of the party we reheated the sealed bags of pork in boiling water, put it in chafing dishes with a small amount of apple juice and vinegar (Darby's right, most of the moisture is fat & collagen). It tasted like it just came off the egg, and we received many complements on the pork. All in all it was a successful and relatively stress free process. Good Luck!