Alternate Show Interpretation: The 2005 Broadway revival, in which all of the characters are portrayed as inmates enacting the events in a madhouse.
The 2012 West End production gave a Setting Update by placing the show in the 1930s.
Alternative Character Interpretation: All over the place. Toby, for one. As the role is vocally demanding, adults are often cast in the part, which makes for the question of whether Toby is a kid or a mentally disabled man. For that note, the motives of the Beadle are ambiguous, whether he's a psychopath who's as bad as the judge or just a police officer who sincerely believes the judge is a good man. Then there's the matter of whether Anthony is a romantic hero who saves Johanna from the Judge or if he's a creepy stalker (albeit a major step-up from Judge Turpin).
Johanna can also be interpreted as genuinely in love with Anthony or just using him as a means to escape the Judge. The 2007 film, for example, went with the latter.
Judge Turpin, of all people, gets one depending on whether his song "Johanna" removed or not. This song shows that he actually tried to resist the temptation Johanna was causing and even seems to imply that she was his Morality Pet. "Johanna, Johanna, I treasured you in innocence and loved you like a daughter".
Depending on the performance, it can also come off as though he's rationalizing what he wants to do.
Does Mrs. Lovett genuinely care about Toby or just as uninterested in him as she is with everyone else other than Sweeney?
The 2014 concert hinted that Toby might be romantically interested in Mrs. Lovett and additionally featured a scene where the Beadle hits on her.
Mrs Lovett in general. Is she a Magnificent Bastard who is just as desperate as Todd to wreak vengeance on society, or is she a Broken Bird who is a victim more than anything? Is she genuinely in love with Todd, or is it more of a Stalker with a Crush deal? Does she mislead Todd about his wife's death because she wants to protect him from the truth, or because, again, Stalker with a Crush? The movie probably gave her the most sympathetic portrayal to date but she's been played as everything from that to complete raging psychopath.
Awesome Music: "The Ballad of Sweeney Todd", "Epiphany", and "A Little Priest", just to name a few. Well... really the entire song list (given the right cast) but bonus points go to "Johanna (Reprise)".
Deliberate Values Dissonance: The judge's sentencing of a young boy to hanging, though he is a four-time offender. The musical obviously wants to criticise atrocities committed in the name of the law that were acceptable back then, as children were treated the same way as adults. This is noticeably shortened to one previous offense in the film to make it even worse.
Ear Worm: Just try to get ANY of the songs out of your head after viewing the theater or movie version. It's bloody impossible (but delightfully so).
Ho Yay: In the movie, there seem to be overtones of this between Beadle Bamford and Judge Turpin. Mostly coming from Bamford's end, though it IS kinda odd that he seems to spend so much time with the judge...
Notably, in the stage musical it's made clear in the reprise in The Barber and His Wife that both Turpin and Bamford have a thing for Lucy. In the movie, however, the lyrics are changed so that only the Judge's affections are mentioned.
Todd probably more so. True, his method of vengeance once he snaps doesn't invite much sympathy, but his reasons for snapping? Just try not to feel the least bit sorry for him, you'll probably find it's nearly impossible.
Magnificent Bastard: Sweeney, himself if you consider that apart from his general wit, he smartly tricked both Bamford and Judge Turpin to come to his barbershop.
Moral Event Horizon: The "Poor Thing" scene with Judge Turpin and Lucy Barker, and the scene where Mrs. Lovett locks Toby in the meat-grinder basement so Sweeney can kill him.
It was made clear that Mrs. Lovett understood what she was doing, since she was crying throughout. Creepy.
Sweeney killing the beggar woman, who ironically turns out to be his own wife, in his haste to leave no witnesses...followed by him almost killing his own daughter for the same reason.
One could argue that he crossed it the instant he decided to give in to despair and murder innocent people unlucky enough to wander into his barbershop.
Paranoia Fuel: A trip to the barber's or a pie shop both made very creepy for the Victorian audience. For the typical modern audiences, this story has made the straight razor unsettlingly best known as a weapon of murder.
The finale reprise of "The Ballad of Sweeney Todd" invokes this trope with its lyrics, culminating with the company shouting "There he is! It's Sweeney!" and pointing out at the audience.
Perhaps today, you gave a nod
To Sweeney Todd, the Demon Barber of Fleet Street?
On the other hand, another way to see them is as a parallel to the Todd/Lucy couple ("she was beautiful, and he was naive", particularly if you take the interpretations where Johanna is crazy into account)
Squick: The whole thing is pretty squicky, but Judge Turpin gets a special mention for "Johanna (Mea Culpa)," where he flagellates himself to orgasm while watching his teenaged ward through a keyhole. While singing. It was cut from the original Broadway production, and, unsurprisingly, it's only occasionally reinstated. When done well, the sequence can be one of the most chilling in the show...which is about serial murder and cannibalism.
"It's only occasionally reinstated..". That's actually not true at all. While the song was cut from the original Broadway and London productions, and the film version, most modern productions choose to put the song back in as it adds so much to Turpin as a character. The song has been reinstated in the concert versions, the Spanish productions, the 2005 Broadway revival, the 2012 London revival, the 2017 Off-Broadway production, most regional theatre productions, and many more.
The song is still only one of two in the score that remains completely optional (the other being the second part of the contest), and plenty of productions do choose to omit it on account of its squick-factor. Sondheim himself has said that the primary reason for the song's existence was because he wanted to be the first person to have a character orgasm in the middle of a song...
Anthony when he bursts into Sweeney's barber shop in the midst of his shaving of Judge Turpin. What was he expecting?
One wonders why Sweeney takes Lovett's advice to be patient in plotting his revenge at heart, spending his sweet time singing along with Turpin about pretty women. What was he expecting? Although... see "Squick" above.
Mrs. Lovett, keeping Lucy a secret from Todd when she kept coming around her shop. Sweeney's shown no hesitation in killing anyone who's crossed him, particularly in regards to his family. What was she expecting?
Pirelli, confronting a man who's been in prison for fifteen years, and blackmailing him. What was he expecting?
Awesome Music: The quiet interplay between Turpin and Todd in the film's arrangement of "Pretty Women," especially as it builds to that crescendo at the very end.
Complete Monster: Judge Turpin is even worse than his musical counterpart. He is a corrupt Hanging Judge in Victorian London and the man who begins Sweeney's start of darkness when, lusting after the then-younger barber's wife, Turpin has him imprisoned on a penal colony for decades of hard labor so he can seduce his wife. When she refuses, Turpin has her lured to his home under pretense of offering to free her husband- but rapes her instead, and steals her daughter as his ward. Turpin guards her jealously, having a younger sailor brutally beaten for looking at her and plans to marry her himself. When she refuses and tries to run away he sends her to an asylum where he knows she'll be mistreated. At another point, Turpin sentences a little boy to death by hanging...and then asks his sidekick, the Beadle Bamford, if the boy was even guilty of anything.
Demoted to Extra: Johanna in the 2007 film version. One of the nine principal characters in the original play with a decent amount of stage and song time, Johanna is reduced to a nearly silent role in the film version and barely does ANYTHING outside of singing "Green Finch and Linnet Bird". Her other major songs and solos (Kiss Me, Kiss Me/Ladies in Their Sensitivities (Quartet), City on Fire, Ah Miss (reprise)) are cut, her portion of the "Johanna" Quartet is removed entirely, she doesn't shoot Fogg in the asylum, and much of her dialogue is trimmed. In the film, she acts purely as a personality-less macguffin and a living motivation for Anthony to do anything.
Not as bad as Johanna, but the Beggar Woman also has a much smaller role in the film. Again, this is due to the cutting of most of her singing material (specifically No Place Like London, City on Fire, and The Beggar Woman's Lullaby), the overall trimming of her scenes (her interaction with Anthony during Ah Miss cuts her "Hey, hoy, sailor boy!" line), and now she doesn't interact with Sweeney at all until her death scene. This renders the overall twist and ending much less effective than in the original play.
Genius Bonus: Pirelli boasts that he had Shaved the Pope himself, while mocking Sweeney that probably thinks it was only a Cardinal, followed by Toby showing a portrait of the Pope. Given that the story should take place in 1846, it was the same year that Pope Pius IX was elected Pope, which would explain how Pirelli might have really shaved the Italian cardinal Giovanni Maria Mastai-Ferretti who became the Pope, giving him the edge by technicallity.
Although the written "Thanks for da Shave - The Pope" on the portrait is rather suspicious on Pirelli's part. Not to mention that we later learn Pirelli is a false identity, giving further evidence that it was all just made up.
He Really Can Act (and sing!): Keep in mind that this movie was released only one year after Borat whenever you see Sacha Baron Cohen as Pirelli. It was also his first role where you heard his real accent.
Hilarious in Hindsight: When the movie came out, it was noted that there were three Harry Potter alums in the film. The actor who played Anthony later played Grindelwald, so that's four. Not to mention that three of the four played Death Eaters, and all their HP characters were, at one point or another, bad guys. Dark Wizard reunion!