Well, about the changes, the Tiger Lady and Master Gracey...

I think they did those out of nessesity for the effect. The Black Panther against a lightly colored woman wouldn't have worked and April against December wouldn't have worked compared to Gracey to a stark white skeleton. Plus, as far as Disneyland is concerned, there is no real defining mark that it is Master Gracey. There is the pin, but it was at WDW.

As for the ball.... ehn. I think they just wanted a neat effect. I just really doubt that the Imagineers were intentionally trying to insert the movie stuff in.