Under normal circumstances, I love going to DTD. But right now I think the best thing to do is to not go to DTD. Nearly all the merch there is either available at the parks or hotels, and there are some very nice original restaurants at the hotels.
OK, re:
Lego store. There is nothing really interesting at the Lego store that you can't find better at
Legoland. And this is coming from a Lego lover! We go to DTD Lego because of the cheap Lego (APs get discount). But if you want a quality Lego time, hit up your local lego store or LegoLand.
Alternate delicious dining options for downtime at Disney:
Food court at POR: Lunch is yummy! Dirty Gumbo, Po'boys and bienes are great. They take Tables in Wonderland too! Reasonable $$
Red River Brewery: You can get a flight of beer brewed by them, and I'll put their cheddar cheese soup up against Canada's any day. Plus it's got a beautiful view of Cresent Lake. Reasonable too.
Beaches and Cream: Two words. Kitchen sink.
Activity options during DTD cray-cray time:
AKL - You don't have to stay there to enjoy the animals, drumming, cookie decorating, and other neat activities there.
Boardwalk and Beach/Yacht Club: bike rentals
Contemporary/Polynesian/Grand Floridian: zippy boat rentals.
Grand Floridian also has an upper-scale version of Basin, if you need your Basin fix.
Anyway, those are some options if you want parking, a view and no headaches.