Like Michael, your plan sounds pretty do-able though I sure hope you've checked schedules. At our HS's in California, Thursday night is usually the Freshmen and Junior Varsity teams playing.
Allow most of the day for the US Space and Rocket Center. If you *really* like space history, try to call ahead to reserve the Marshall Space Flight Center tour. It's extra cost but to us, it was VERY worth the money. They only do one tour a day and sometimes they fill quickly. You can reserve that tour by calling the US Space and Rocket Center 30 days ahead of time. Here's some information you need.
Donna