The big question about captain America cival war is will spiderman play the role he did in the comic version. His role in the comics was he was torned between the two sides. He had great respect for captain America and ironman. He is the voice for reason for this story line.
But the MCU spiderman is a new spiderman that has yet to be developed. He hasn't even had one MCU solo film and he is already getting a major role in one of the biggest crossovers of Marvel's history. So maybe he should get a introductory role. as being a big spiderman fan we do not want see him rushed.
In the end I believe marvel can pull this off. If they can turn ironman into alist hero and make in unknown group of antiheros a box office hit then this could work.