Corrected entry: There's no reason Verruca's dad or any of the other characters for that matter couldn't have climbed over the gate to save Verruca from the squirrels without resorting to the keychain.
Corrected entry: At the start, English-label bars are sent to Tokyo. Later in the news, however, chocolate in Tokyo is shown to have Japanese labels.
Correction: It's certainly possible to have both a native language and English bars in one country.
Corrected entry: After all five kids find the golden tickets it's revealed they have to be at the factory on a specific date and time according to the ticket. So what would Wonka have done if all the tickets had not been found by that date? Keep in mind it is also revealed that the "Russian" ticket was a fake which was discovered just before Charlie found the actual remaining ticket. If he had not found that ticket or it was revealed that the Russian ticket was a fake after the specific date had come and passed there would have been only 4 ticket winners to arrive at the factory, so what would have Wonka done then?
Correction: This is a question and not a plot hole. The same scenario is present in the book and original movie. Wonka could have simply proceeded with the tour with the 4 children or pushed the date back. Although the fact that very specific kids, including Charlie, found the tickets means there was more at play than sheer luck and so Wonka knew all 5 real tickets would be found in time.
Correction: Know this: Wonka is a genius. No biased, he just is. He has set the entire day up to see who the "good egg" and the "bad eggs" are. Mike TV was shown the TV room. Verucca was shown animals. Violet was shown the gum room. Wonka most likely knew all the tickets were going to be found. The first movie is better in terms of explaining how everything falls into place, but know that Wonka knew what he was doing.
Corrected entry: Throughout the movie the size of the Oompa Loompa's varies in scenes, between shots where there are full sized characters, and in shots with no full sized characters.
Correction: Maybe Oompa Loompa's are like humans, you get shorter people and taller people so this would explain the size difference.Or maybe the taller Oopma Loompa's are adults while the shorter ones are children.
Correction: Good theory, but we know from Willy Wonka his self that Oompa Loompa's are all small. That is even what the children exclaim, that O. L's are all smaller than them. So having Oompa Loompa's of different sizes is fine, but not with drastic measures. Maybe if they were from different places, but Wonka says that they were all from the same village with the same leader.
Correction: Had Veruca's dad or any other part of the group tried to save her, the squirrels would most likely have attacked and knocked them into the garbage chute as well. Also note, that each time something happens to the other kids, Willy doesn't do anything as he sees them as being rightly punished.
Veruca looks about 6 or 7. These are adults watching. Willy didn't know until after the song that she was not going to die. He had no excuse.
I think that you have missed the moral of the story, completely. Wonka set the entire day up, by the way, wanting to find the pure child who could run his company for the good of everyone else, not him or herself. He knew Verruca was not going to die (his crazy personality let everyone believe otherwise, though) but he wanted to punish her, of course.