Hi, Amy!
May is an absolutely fabulous time of the year to visit the Walt Disney World Resort! The weather is normally gorgeous and the humidity is not usually out in full force yet by that time. I actually think that you've got some great dates picked out there.
You're right,
Star Wars Weekends do have quite a large impact on crowd level at Disney's Hollywood Studios, but since you'll be visiting another Park on the on the kick-off day of that event, you'll be just fine.
I also have some more great news for you! The
Epcot International Flower & Garden Festival is going this year from March 6 to May 19, 2013, so you'll be able to spend some time there enjoying all of the beautiful blossoming gardens and vibrant topiaries. You'll also be able to take advantage of the Flower Power Concert Series. Be sure to pick up a Times Guide on your way in to Epcot for show times.
I hope this helps and please feel free to come visit us again if you have any more questions we can help with!
Have a Pixie Dusted vacation!
~Jackie