There's no way Leah is SEI. The peppy cheerleader... SEIs are more, well, shy. Leah strikes me as ESE. I agree though Juno could be ILE. Not sure about your other examples.
And I agree in general there are a lack of ILE-SEI duality movies because of a lack of drama... most conflict is about very abstract beliefs, values, or even long-range plans, which would be tough to show in a movie. Also SEIs are the champions at avoiding disputes and making ill-temper go away , so it'd be tough to keep them in character and show them deal with drama... Alphas in general are laid-back and less inclined for drama... and lastly most ILE-SEI disagreements occur behind closed doors, so it'd be tough to include other characters in a movie format.
To offer my opinion on the topic... last night watched Disney's classic "Beauty and the Beast" with my niece.
Beauty = EIE (ENFj) and the Beast = LSI (ISTj)