Cap was handled great for the most parts IMO. The only really bad plot point is when Cap and Tony have their dispute at Berlin after Bucky has been taken into custody. Cap seems to be okay with signing the Accords until Wanda's "imprisonment" is mentioned, and immediately starts to argue with Tony. It's a major point in the movie where the situation could have been de-escalated, and Cap uses Wanda as excuse not to. That was handled awefully by the script IMO.
Oh, and he let an airport gate collapse onto a teenager while he couldn't be sure on whether Peter would be strong enough not to be crushed by it.
I have another few questions after watching the movie:
1. What the hell was Crossbones' quest about? He randomly wanted to steal biological hazard, then just blows himself up? I mean – why? Who did he work for? Himself?
2. Where did Black Widow go after the Airport fight? Was she also in the Raft prison? I didn't see her...
3. How the hell did all the guys get from Bukarest to Berlin in what seemed to be a short time? That's a multiple-hours-drive. Also, why go there even in the first place? The movie is all about "respecting country borders" and Romania just lets the CIA(?)/UN Taskforce(?) take all these people to Berlin?
4. Zemo's plan depended on so much coincidences and things that could have happened very differently. Did he find out about the planned Accords and then make his plan up on the go? (He definitely is the MCU version of BvS Lex Luthor) Also: He mourns about his family and then blows up an UN building full of people? A little more insight on if he thought that it was a necessary evil or simply didn't care would have been nice.