Black Widows hex: She flashes back to her training as black widow... if you watched Agent Carter, you get a sense of little girls fighting. Her spy training and fighting training started at the dance school.. It was a secret place for training young girls to become spys.
1) At the end, Tony and Cap have a conversation outside of the Avengers headquarters (Academy?). At the end, Tony drives off in his orange Audi R8...
Cap and Natasha talk about the new team, which then you see The Falcon, The Scarlet Witch in her new red outfit (different from the one in the trailers), Barton, and The Vision...
2) Big twists.... yeah... how Ultron is created was cool. But how The Vision was created, even cooler! How the twins switch sides. How many Ultrons there are.
3) Civil war - I think all the heated words between thor, Cap and Stark ... it's all dropping hints towards taking sides. Then at the end you see a new Team Assembled by Cap
The Vision wields Thor's hammer. Steals the scenes!
1) Thor chokes Stark because Ultron was created and is now running around the world inhabiting different robot forms. Out of frustration, Thor chokes Tony and calls him out on it.
2) I didn't see two much of the split personality angle. Banner and Hulk are the same as in the last movie. The difference is Hulk is more in control and can take direction from the other Avengers. He can be calmed down to Banner again by Natasha talking to him. A psychological thing.... where she also touches his hands to make him come down to Banner again.
Hulk only rages out of control with Wanda puts a hex on him.
3) Thor stayed here after Thor 2. He seems to blend into civilian life (not shown, only referenced in jokes). He does leave to Asgard to investigate the visions he had when Wanda put a hex on him.
4) Nick Fury was in hiding. Seems like he was working with someone, tracking down leads, etc. He seems well informed. Even though they don't mention it... i wouldn't be surprised if he's in contact with Coulson at some point (a later AOS episode perhaps?) or maybe he's in touch with Deathlok.
5) Yes, i would say so. When you think about what he is and what his philosophy is and what he wants to do... it's quite scary. "Ultron" like discussions have been in the news in recent weeks... Bill Gates, Elon Musk and Stephen Hawking have all warned us about AI and machines becoming aware. When you think of all this... he's quite scary. In the movie is just darn right cold and wants to destroy man. He thinks he's human.
Falcon and War Machine both show up at the party scene at Avengers Tower. Then they're both gone from most of the movie.
I have no idea where the Falcon went off to. Maybe i missed his dialogue about that. But War Machine shows up in a scene at the end when the Helicarrier shows up to evacuate the people of that city in Sokovia. He helps fight the many Ultrons in the sky and keep the Helicarrier safe along with Tony Stark.
At the end, Falcon shows up at roll call when they announce the new team.