Question: Why did Diana destroy the mall's security cameras, and why did she want the little girl to stay quiet?
Answer: This was long before the age of superheroes, when everything was normal and meta-humans were just theories in a lab. It was her appearances which stated it all. Remember the tagline, "The Dawn of Justice Begins with Her."
Question: What was the point of having Steve take over the other man's body instead of just returning from the dead in his own body? Unless I'm forgetting something, the ramifications and ethics of him taking over his body are never explored in the film, so it has no effect on the plot, and Diana renouncing her wish would not play out any differently, because Steve goes away either way.
Answer: There's no definitive answer (and hopefully others will weigh in here with opinions). Diana had wistfully wished that Steve was still alive without ever knowing or intending it would happen, nor did she have control over the form it took. By happenstance, another man's body was possessed. The movie's timeframe is too short to know what ethical decisions would eventually have been made over Steve's soul inhabiting another body, though he does mention the moral dilemma it poses. After a reasonable amount of time, they would have to decide if Steve should continue in a co-opted body. Character-wise, it shows Diana's anguish over losing Steve yet again in order to defeat Cheetah. Steve's soul being brought back may foreshadow his resurrection in another way in the next film. Chris Pine (Steve) is reportedly returning for Wonder Woman 3.
Answer: I don't think writer Patti Jenkins is familiar with the Wonder Woman comics in so much detail that she was actually trying to pay homage to previous Steve Trevor story lines or hint at what's truly happening, but maybe. Steve Trevor has died and come back to life before in the comics. He's never possessed the body of another person, but once a brainwashed Eros possessed his body and once when Trevor came back to life, he dyed his hair black and went as Steve Howard. It does seem like Jenkins left things vague to bring up later, like with Cheetah.
Question: Depending on child labor laws just how did they get the young Diana actress to do her own stunts?
Answer: Lily Aspell, (young Diana), performed many of her own stunts. She is naturally athletic and was already an expert equestrian rider (her parents and uncle are professional jockeys). Stunts are carefully coordinated, and she would never have been allowed to do anything dangerous. Stunt doubles perform the more dangerous action scenes. Often, CGI superimposes an actor's face over a stunt double's body. Safety harnesses and suspension cables are used and later removed digitally. Actors also perform many scenes in front of a "green screen" and special effects are added later to look like an extreme environment. I once observed a movie scene being shot. What looked like a wild car chase in the move was actually filmed with the vehicles driven at slow speed. The action was sped up during the editing process.
Question: Why does Wonder Woman need the armor?
Answer: When Barbara Minerva wished to be just like Diana, she was granted the same strength and powers as Wonder Woman. Barbara additionally became less humane and even more powerful and dangerous after morphing into "Cheetah." Diana needed the armor to outmatch and defeat Barbara. She was also expecting to fight a multitude of soldiers to get to Max. The armor was originally Asteria's, who needed the extra protection when she battled an army to save the other Amazons.
Question: How did Antiope know Diana cheated? Why allow her to compete in this contest if she wasn't allowed to train, at first, in the previous movie?
Answer: The competitors had to light up the cloth banner beacons using their bows and arrows. Diana finished the course but missed one blue beacon by taking the cave shortcut, so the general grabs her and disqualifies her.
Answer: In the first movie, Diana was much younger and unready to start combat training. In the second movie, the flashback scene takes place some years after that, and Diana has since grown and been in training. During the competition, there were observers along the entire course to ensure that everyone followed the rules, attended to any mishaps, etc. If anyone cheated or failed to complete the required tasks, it would immediately be reported to Antiope.
Question: So when we see Cheetah again she's sitting there seemingly human once more. Does she still have her other powers?
Answer: She feels sad for letting her personal fears and greed for power consume her. As for getting home, like Robert Shaw said at the end of Force Ten from Navarone, "We have a very long walk back home."
Answer: The way I interpreted the ending (which is up for debate obviously in a different forum) was it was the act of Max Lord renouncing his wish which caused Barbara to lose her cheetah powers. It also caused every other unrenounced wish to be lost. Barbara wouldn't have been able to hear the broadcast or Wonder Woman telling the world to renounce their wish (it would also explains how all the wishes were rescinded without everyone having to be listening to Max). It's unclear if she lost her initial wish though (to be more like Diana). It's possible we'll find out what happened to her in a follow up Wonder Woman/Justice League film, but I highly doubt it.
Answer: No. When everyone in the world all renounced their wish, Barbara renouncing her wish would have resulted in her losing both her Cheetah powers and the ability to be more like Diana.
Well then why does she look sad for having done the right thing and how's she going to get home?
Sad because she's lost her powers, her getting home is her problem and not plot-relevant.
Question: Why is Asteria living among regular people? She couldn't return home?
Answer: This was not explained in WW84, so any answer would be speculation. It is rumored that Lynda Carter, who played Asteria, may appear in Wonder Woman 3, which will hopefully explain her backstory. She is probably similar to Diana, who also chose to live among regular humans, secretly using her powers for good.
Answer: At this point in time, her gig as a superhero is not public knowledge, and she wants it to stay that way.
Phaneron
How would that accomplish anything considering there were many people in the mall who saw what happened?
It really wouldn't, but then again, the writers didn't put much thought into this movie.
Phaneron
As the other answer indicated, Diana/Wonder Woman wasn't yet known publicly as a super-hero. A video recording is different from eye-witness accounts of what people actually saw or believe they saw. Memories are faulty, they fade, and everyone sees and remembers things differently. Regarding the child, I interpreted it as Diana just motioning in a friendly way for the rather precocious girl to stay put, behave, and quietly wait for her mother.
raywest
In my opinion, it wouldn't, and it's just another example of the shoddy writing in this film.
wizard_of_gore