I've been Memorial Day weekend many times, and honestly, it's not bad. It's much less crowded than spring break or early June. Star Wars weekend will be a total madhouse, but it seems like you'll have plenty of time there. Just remember that even though the posted opening time for the studios all weekend will be 8:00, they will open the park by 7:30, so if you want to do Jedi training academy, toy story mania, etc, I would plan on arriving no later than 7:15. Last year we walked up just as they were opening at 7:30 and waited 45 minutes to sign up for Jedi training. The character greetings usually start around 9, so I would start lining up for them after you've signed up for JtA and maybe ridden toy story. That was our strategy and it worked relatively well.