My son (He's 21, though, not 7) and I who have visited the Magic Kingdom many times are doing a day there next month. We are just doing our favorites (skipping the other attractions) -- actually we would do Big Thunder Mountain on top of the list that I'm giving, but it happens to be under refurbishment for our visit).
Anyway, here is our custom one day touring plan, just in case that gives you any ideas. This is just our list of what we think are the best attractions at the Magic Kingdom and only our personal opinions regarding what is most worth doing We can get all this in between 9 a.m. and 4 p.m. on a moderate crowds day. Then we will leave for four hours and come back for fireworks. I'm sure we are leaving out some people's favorite attractions and are probably doing fewer things and having a shorter day (really just 8 hours) than many people prefer. Like I said, this is just our preference and the kind of day we like.
We weren't able to get a fast pass for 7DMT, but got FPs for Haunted Mansion, Under the Sea, and Space Mountain, our next three longest predicted lines. Touringplans.com if you get a subscription gives great descriptions of all the attractions, gives author rating, and gives ratings by age group if you would like to see other people's thoughts on what they like best. I'm not sure if you need a subscription or not to look at that. I know you can do custom touring plans on the site without a subscription.
Anyway here are our must dos, the order we are doing things in, and our planned lunch and dinner breaks. // Jungle Cruise, Pirates, Splash Mt, 7DMT, Small World, Haunted Mansion, Mickey's PhilharMagic, Under the Sea // lunch at Casey's corner, one hour to shop on Main Street USA, the 3 p.m. parade (Festival of Fantasy), Space Mountain. Next we will take a four hour break -- go over to Wilderness Lodge - do a Counter Service Meal at the Roaring Fork snack bar/cafeteria, relax, walk around the resort. We'll then go back into the park at 8:00 p.m. to be there at 8:30 to see the projection show at 8:45 p.m. and the Wishes fireworks display at 9. If we feel like going back earlier, we can do that.
We put in what we are doing in a custom touring plan on the touringplans.com website that helped up pick our fastpasses and have a good estimate of our timing of things.
We love the Magic Kingdom and I know we will have a Magical day!