The Hydra research base appears to be located in Pittsburgh, PA. When Jemma Simmons and Bobbi Morse jump from the rooftop to land on the Quin-Jet, the skyline appears behind them. At least four buildings in that shot match ones from the Pittsburgh skyline.
There's a brief reference in one scene at the Hydra lab of a comic book character named Bessie the Hellcow
The location used for the wedding reception appears in a Marvel film as well: Daredevil (2003). The room is the Rendezvous Room of the Millennium Biltmore Hotel (downtown L.A.).
Both Adrianne Palicki and Cobie Smulders (Maria Hill) have portrayed the DC Comics character Wonder Woman: Adrianne had done so for the aborted live-action Wonder Woman (2011), while Cobie had voiced her for The Lego Movie (2014) and had also been attached to a proposed live-action film written by Joss Whedon.
Two minutes and twenty seconds pass in real time on the two-minute timer Raina (Ruth Negga) sets on her phone in the restaurant.