And don't forget the campfire and singalong at Fort Wilderness. Chip and Dale will be there. You can get marshmallows and sticks for very little and the usually show a movie as well. The campfire and movie are free, there is a small charge for the sticks and marshmallows. You could also bring your own.
Puchase inexpensive treats for each of them for each day. Leave them in their rooms with a note from Mickey. Glow necklaces for the night you will be in EPCOT, Disney Pez dispensers, animal crackers for the day at AK, autograph books with fat pens, lanyards from Staples and one or two pins to trade with CMs.
Decorate and wear matching shirts. Get a group photo taken by a Disney photographer on Main Street USA with the castle in the background. Purchase the photo and a nice frame for a great souvenir of your trip.
Look for hidden Mickeys in each of the parks and resorts that you visit. Give points for each one and keep track of everyone's points. Make a button declaring their success for the winner to wear the next day (have it say something like "Jones Family Hidden Mickey Champion"). Watch how many people comment on it.
Take the tour of the AKL. The kids will love it as much as the adults. There is also storytelling in the AKL lobby most evenings.
Have each person keep a journal either by writing about it each evening or by drawing a picture. Share the journals with each other once you get back home. It's fun to see what each family member found to be the most interesting parts of each day.
That's a start. If I think of more, I'll post again. The magic is in the time that you spend together, not the money that you spend.