You can park at the hotel. The security guards are very good there about allowing non-guests to park there as there is a lot to do. If you park at Epcot (depending on the time you go) you run the risk of not being able to get back to your car.
There are various resturants on the Boardwalk:
ESPN Club, Spoodles, Flying Fish, Big River Grille
There are 2 "night clubs":
Atlantic Dance and Jellyrolls. Atlantic Dance changes it venue often, but Jellyrolls (must be 21 to enter) is dueling pianos and is a lot of fun.
There are activites:
You can rent watermice, pontoon boats and canopy boats (during the day). You can rent bikes and the multiple seat Surrey Bikes. There are also Carnival style venues along the Boardwalk itself which are fun, Different games, face painting, that kind of stuff.
Night time is definetly more alive, but anytime is fun just to check it out. We usually go for dinner and then go to Jellyrolls.