We did everything at Magic Kingdom with our 3- and 10-year old daughters when we went the week after Memorial Day this year. Even with a couple hours of rain.
We did skip the Peter Pan ride and Splash Mountain because of the obscene wait times. Our girls weren't super interested in doing them, and the 3 year old was too short for Splash Mountain anyway, so we didn't think the waits were worth it, and we're going back in December. We could have done Peter Pan if we wanted to wait in a 2-3 hour line, but I can't imagine why the Peter Pan ride is that popular. We are going back in December, so now we know to get a fast pass for that one.