It's Tough to be a Bug has giant spiders that hang over your head from the ceiling and HARD points that jab into your back as "bees" sting you. I would say skip it.
Must sees .... there are too many! Hmm...I would say at MK do It's a Small World, Peter Pan, Pooh, and Philharmagic in Fantasyland if you can; Hang out in Toontown and see the character's houses, Buzz Lightyear would probably be fun in Tomorrowland. At Epcot, do Figment, Living with Land, Ellen's Energy Adventure if the kids like dinosaurs, the Living Seas and Turtle Talk with Crush, and El Rio Del Tiempo in Mexico is nice. MGM ABSOLUTELY go to the Beauty and the Beast show and Little Mermaid show. The Muppet 3-D show is cute and kid-friendly too. And at AK, whatever you think your family would enjoy...we don't do much at AK. The safari is cool, DinoLand is cool...that's about it for us.