Re: James Buchanan Barnes aka The Winter Solider
What if the character of Bucky Barnes was used (in the first Captain America movie) to show how Steve Rogers, even as Captain America, was socially awkward and an outcast. Like Bucky, a 17 year old kid, is a ladies man and friends with everyone. Where as Steve Rogers, even as Captain America, feels separated and unable to connect with his fellow soldiers or women. (Not that women troubles would be a huge part of the movie, and that Cap is a social leper.)
It could just show that Steve is more introspective, maybe from years of being a social outcast prior to the serum, and Bucky is more a social butterfly.