[potential spoilers]some of the highlights:
- The Russos liked the idea of testing the relationship between Steve and Natasha, which had been built up in Cap 2. They say her head is with Tony's side but her heart is with Cap.
- The Russos say they played with the history of Tony and Steve. "By the time Tony Stark was born and grew up, Captain America was a legend. We’re tracing the history between these two characters. It’s very interesting. It’s a sick, complicated relationship.”
- Falcon is deepening his relationship with Cap in this film, but questions also arise about the change in dynamic with Bucky back in the picture.
- The Russos are vague about the Black Panther's role, just saying he has his own reasons for entering the conflict.
- There's a very important reason Steve is holding onto the helicopter in that scene in the teaser. "There’s something very important happening in that scene and for us it really represented his struggle as a character, one man pitted against a helicopter that’s trying to take off. Can he stop it? And what are the limits of his strength? For us, it’s one of the most powerful shots in the movie and it’s Chris Evans, who works very hard to physically exemplify this character."
- The Russos say the movie's theme is betrayal. “The movie’s extremely emotional. It hinges on that emotion, and on a very personal level we didn’t want the movie to become about politics and people arguing about platitudes. The third act is built around a very personal moment between these characters.”