I agree that most won't spend the money if they are not "into it," but there is the stranded "Mom" problem. The big problem is keeping the experience immersive given that you can't stop people from being people, and I really don't see how you can REQUIRE a costume. But, I think you can get around a lot of it with the story telling aspects of the thing. I just made this up:
"The Rebel Alliance has gotten word that the Empire has learned that some VIP or another has been living in disguise on vacation planet Porlandio. In order to protect the citizens of Porlandio, the RA have scooped up its citizens to move to deep space until the danger passes. The RA can use your help! While you are our guest, if you want, take this opportunity to try out to become a soldier or and officer with the RA, blah, blah, blah. But be cautious of the spies and other dangers lurking around every corner."
That lets people in shorts and crocs to seem to be naturally present, and allows for people to choose their level of participation. I'm sure Disney would do a better job, but this kind of thing seems like it could be an option.
"The Rebel Alliance has gotten word that the Empire has learned that some VIP or another has been living in disguise on vacation planet Porlandio. In order to protect the citizens of Porlandio, the RA have scooped up its citizens to move to deep space until the danger passes. The RA can use your help! While you are our guest, if you want, take this opportunity to try out to become a soldier or and officer with the RA, blah, blah, blah. But be cautious of the spies and other dangers lurking around every corner."
That lets people in shorts and crocs to seem to be naturally present, and allows for people to choose their level of participation. I'm sure Disney would do a better job, but this kind of thing seems like it could be an option.