1) would depend on where you're staying. If you're staying in the downtown area, public transportation is fairly accessible, but if you're staying outside of the downtown area it gets pretty iffy. You wouldn't be able to park in the actual tailgate lot, you'd have to pay for parking in a different lot.
I checked out the tailgating section of the site and it looks pretty fun.
Couple of questions I am hoping someone can answer:
1) If I only need to bring food and beer, is it possible to go down there without driving? Is public transit to the stadium any good?
2) Do I need to buy tickets or something to get in?