My daughters are talking about buying two Tinker Bells to play together in the Toy Box, but I don't know if this is possible and don't want to waste money if it's not.
Can you return unopened figures? I think the game will recognize the figure even if it is still boxed. You could buy one and try it and then return it. I know Best Buy has a good return policy in general. I'm not sure about the specifics for this item.
Yes, I confirmed that it's possible (Wii U).
I was even able to play the Incredibles play set with two Mr Incredible figures as player 1 and player 2 at the same time.