Hi Sue,
Love that you're counting down the days because your vacation will be here before you know it!
Downtown Disney is a great place for pin trading.
Disney's Pin Traders located at Disney's Marketplace is the biggest pin-trading location with the largest assortment of pins anywhere around the Walt Disney World Resort.
In addition to trading with other Guests, your kids can trade pins with Disney Cast Members. According to the Disney's Pin Traders' rules, Guests may trade a maximum of 2 pins with each Disney Cast Member throughout Walt Disney World Resort.
Although not as big as Disney's Pin Traders, you can also find trading locations at Downtown Disney inside the World of Disney and also near the DVC Information Center hear Bongos Cuban Cafe on the West Side.
You are welcome to leave Blizzard Beach and renter as often as you'd like on the same day. You will not have to get your hand stamped. You'll just need your ticket to renter the park.
Wishing you many magical memories :-) Allison