What is on your list of things to eat? Dole Whip and School Bread are my only real must dos. I tend to try new restaurants each trip instead of hitting favorites. I would highly suggest Columbia Harbor House if only for the wonderful second floor which is likely my favorite place to sit back and relax in MK.
What rides must they ride? MK: Splash Mt, Space Mt, Big Thunder Mt, Pirates, Mansion, Buzz, and Peoplemover. HS: ToT and Star Tours. AK: Dinosaur, Everest, and Safaris. Epcot: Soarin and Spaceship Earth. You could say Rock 'n' Roller Coaster, Test Track or Toy Story Mania, but if their waits are very long, or you can't get a good FP+, they are all skippable (in my opinion).
Any show must they watch? American Adventure (I think it's one of the best attractions in the resort) and Phillharmagic if that counts.
Are there any things you'd do in order to tease them? Other than Beverly soda, I've got nothing.
Are there some things you'd go out of your way to avoid showing them? Or suggest to do something else on? Just avoid wasting your time on bad rides, especially if your time is limited. If you have a good amount of time on your hands, try to hit as much as possible. I mean the only attraction that might make someone angry is SGE or Figment because of the smells.
Is there a must see resort? I'm not that resort crazy like many people on this site, but I personally love the feel of Wilderness Lodge the most since it seems much more quaint than any other resort. If you have time, take a boat over there, you'll enjoy it.
Any other things you feel they must do or try? Know that taking it slow is not a bad thing. I always prefer a midday break and a few shows to get off your feet. All my favorite moments were those when I just calmed down and appreciated the environment. This is especially true at night when all of the parks really come to life and seem so much better. Lastly, I would also plan to spend the least amount of time at HS since there isn't really much there anymore.