These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Taking the tone of Tarantino's films into consideration the majority of the protagonist usually falls under the Villain Protagonist or morally gray category. Up to the individual as to how they see Django in that.
Anti-Climax Boss: Calvin, who is simply shot in the chest by Schultz, without seeing it coming.
Stephen also, he had only a few henchmen who are easily dispatched, and Stephen himself was unarmed. Stephen is then kneecapped and left to die with some dynamite.
Award Snub: Tarantino didn't receive an Oscar nomination for Best Director; though he did win one for Best Original Screenplay.
Many also complained about Leo DiCaprio not getting a Supporting nomination for his wildly against type performance.
Designated Hero: Some people (case in point) felt that Django was kind of a dick who permitted or committed all sorts of terrible deeds because he thought seeing his wife was more important than all the murder, torture and slavery in the movie.
Foe Yay: Django and Billy Crash. None of Candie's henchmen like Django, but Billy is the one that picks fights with him. Django in turn likes mocking him. Their arguing also has a reference to "walking in the moonlight" and has the line "You wanna hold my hand?" Then there's the fact that Billy seems to be rather enjoying himself when he's about to castrate the naked, Bound and Gagged Django and has his hands on his genitals.
Django mentions that being a slaver is the lowest a black man can sink, even lower than the "head house nigger, and that's pretty fucking low." In Real Life, house slaves enjoyed a much higher standard of living than the field slaves, earning them a lot of resentment from the rest of the slaves. Stephen, as a villainous head house slave, is basically a stereotype from a 19th century field slave's point of view. In addition, Freedmen were viewed with contempt from whites, but black slaves also showed contempt, as exemplified by Stephen.
During the scene in which Schultz buys Broomhilda, Lara plays Beethoven on the harp. There is a somewhat controversial theory that Beethoven was part black. Beethoven was also an admirer of the French Revolution's ideals of freedom, equality and fraternity, put music to Schiller's ode to universal brotherhood ("Ode to Joy") in his Ninth Symphony and penned an opera, Fidelio, which is about a loyal wife rescuing her husband from the chains of captivity. It is almost a motif that the Candies are fans of European authors and composers that would loathe them if they met face to face.
What are two Australians doing in the middle of the Deep South? Well, remember that they work for a mining company, and the US experienced its first immigrants from Australia in the early 1850s as miners trying to strike it rich in the California Gold Rush. Presumably these two are former Gold Rush miners who decided to move on to other mining opportunities in the US. The Australians being racist also isn't a stretch - violence and racism against aboriginals in the same time period was virulent.
Schultz tells the freed slaves in the intro to follow the north star. The star was heavily used by the Underground Railroad to lead escaping slaves to Canada.
Candie's "Obedience Skull" scene is based on actual pseudoscience called "phrenology." Phrenology was used by actual white slave owners to justify the institution of slavery.
Django's blue outfit is modeled after Thomas Gainsborough's famous painting The Blue Boy.
Idiot Plot: The entire second half of the film is predicated on the idea that Schultz believes Candie won't just sell him a slave, if he offers way more than she's worth. This is justified, however, as Schultz's flaw is his Complexity Addiction.
Only a man like Schultz can not only get away with shooting a local sheriff in the middle of the street, but convince the town to compensate him for it!
Stephen. He turns out to be the true mastermind behind Candieland, figures out who Django is, what he wants, and how to turn the situation to his and Candie's advantage. All this while putting up a brilliant facade. Most unique of all is that he's not portrayed as a schemer, but a very devoted slave to Candie, bordering on paternal affection.
It is unknown when Calvin Candie crosses it, but one of his cruelest deeds in the picture is ordering the Mandingo slave to be mauled by dogs, just in case you haven't already pegged him as irredeemable from his Establishing Character Moment even before his face is shown. That said, he certainly crossed it by the time he insisted that Schultz shake his hand after forcing him to buy Broomhilda, which compared to all his other actions comes across as minor but is more or less the tip of the iceberg; he had forced Schultz to go through with the transaction on pain of her death, and he should've just considered it complete once everything has been signed and the money transferred considering that Schultz is so disgusted with his treatment of his slaves (including the aforementioned Mandingo slave) that he actually refused to bid him "auf Wiedersehen" (which in German means "until we meet again") upon parting ways with him. Normally, sticking to tradition wouldn't constitute a MEH, let alone a puppy-punting incident, but Candie tried to force it on a buyer who clearly wanted nothing more to do with him. No wonder Schultz "couldn't resist" popping him off while pretending to shake his hand.
Billy Crash crosses it by nearly burning Django's genitalia off (but for the intervention of Stephen) - that is, if he had any chance of redemption to begin with.
Stephen's actions - thwarting Django's reunion with his wife out of spite and then devising the cruelest possible death for him - possibly constitutes a crossing.
Padding: At almost three hours in running time, the film is certainly not in any hurry. Some sequences stick out:
The scene with the proto-Klan, once they establish that they are going after Schultz and Django, turns into a discussion about the impracticality of the hoods.
Schultz pours two glasses of beer, and we see every mechanical process required in that action.
Candie takes two plates of white cake and walks all the way across the room to meet Schultz.
The writing up of Broomhilda's bill of sale could be seen as this or as a necessarily long scene to draw out the characters and audience's tension.
Slavery is horrible (obviously) but this film really pulls out all the stops to show us exactly how hideous the whole institution is, and why so many people (Stephen especially) fought tooth and nail to keep it.
The Overly Long Gag where Big Daddy tries to describe to his slaves how to address Django since he's a freed Black Man. The general absurdity about it is pointing just how stupid racism is.
They Wasted a Perfectly Good Character: One of Candie's trackers is a mysterious, unnamed figure who wears masculine clothes and a mask but who is quite obviously female. Late in the film she gets a lingering close up quietly staring at a stereostopic photo, implying she is about to enter the plot in a big way. Seconds later she is unceremoniously shot dead along with the rest of the goons. She was originally planned to have a bigger role, but that was cut out due to scheduling difficulties. It would be revealed that she wore the mask to hide the fact that half her lower jaw had been blown away.
What an Idiot: The Australian trio. They get killed by trying to be as accommodating as possible.
One of the Le Quint Dickey guards sports a well-worn Confederate cavalryman's kÚpi...in 1859? What?
Played in-universe. As a costume for his decoy valet character, Django decides to wear a very bright blue suit with breeches and square-buckled shoes, modeled after Thomas Gainsborough's The Blue Boy. Even the slaves think it's stupid: "You mean you wanted to dress like that?!"