You may have already done this, but make sure to see the entertainment. All three of my children (one of them 9) love Imaginum (living statues) in Italy, A Chair Act and Le Mime Roland in France, Miyuki the candymaker in Japan, the Chinese acrobats and the World Showcase Players in Great Britain. Dad and I also like Voices of Liberty and American Vibe in America, but the kids are less enthusiastic.
We also eat a lot in World Showcase -- churros in Mexico, pretzels in Norway, ice cream in France, Kaki Gori in Japan, etc.