I totally disagree with the analysis of Donald. He may throw tantrums like a child, but like a child, he ultimatly respects his elders and understands the value of his relationship with Mickey.
He has never been charactorized as anything more than a friendly rival. No malicious behavior truly meant to hurt Mickey has ever been documented.
Figment as a gateway character / advisor / muse that guides Mickey would be great.
I also do not see the Song of the South characters being baddies. Especially as described. Although it would be a wild logical leap, in the end they would be upset because the suppression of the inferiority of non-whites message. Disney would never sign off on this story being used in any way that could cause a racial backlash, no matter how far fetched it may be.
Toad remains a Huge Disney character. Mickey's Christmas Carol is basically a Wind and the Willows Elseworlds tale.
With the scope of the story, there will be some kind of WED appearance. In what capacity, who knows, but it will be made. If KH 2 had not use Yen Sid, that would be a lock.
The game seems very based on color or lack there of. So, wonderfully world of colored characters as foes goes against the whole concept of the game.