On the subject of Sasuke, there's his original Face–Heel Turn when he defected to Orochimaru. Did he abandon his friends because he felt they were making him weak as he claimed; or was it because he felt as if he was betraying the memory of his family by forming new bonds?
One can see the Hyuga main family as jealously guarding its power against the branch relatives and promoting infighting, or the branch family as being jealous and presumably no better than the head family were one of their own number to take leadership. This may not apply to Neji, considering that his grievances with the head family were mainly based around what happened to his father, and he's willing to get along with them after learning the truth. Hanabi, Hinata's younger sister is usually characterised accordingly in fanfiction, depending on the writer's intent.
There's also debate surrounding the two families themselves, since the manga is fairly vague about the specifics of the clan's politics. How far does the servitude of the branch family extend - are they actual slaves with no control over their lives, or are they more or less free to move about when there are no crises? Naruto's promise to break the clan's cycle of hatred also varies depending on interpretation; some view his promise as being a broken one as the two branches continue to exist, while others consider his promise to have been fulfilled when the main and branch families fought side-by-side during the War Arc.
Itachi.
His motives have been questionable since his first appearance, and after certain revelations, the fandom has found a million ways to interpret his behaviour.
The greatest and most tragic hero in ninja history? Or a selfish, misguided child who didn't even consider dialogue as an option? Someone perhaps even more brainwashed than Sai who committed war crimes because he was ordered to. And maybe, also the greatest traitor of them all, since he betrayed his oppressed, discriminated family. One who kept betraying it by traumatizing his younger brother, whom he claimed to love. So selfish as to not kill him because he couldn't but never stopped to think how all of that would impact him.
Naruto's interaction with Sasuke is definitely subject to this.
Is it the effort of a good friend who sees, unlike his compatriots, that Sasuke is not beyond redemption and that redeeming him is key to breaking the cycle of violence in the Narutoverse? . . . Or is it the desperate act of a deluded fool, a boy who refuses to grow up and face the fact that difficult choices are sometimes called for among ninjas, a boy whose lonely, dejected childhood has left him with an unhealthy attachment to someone who has openly threatened his home and other friends?
Then let's add some more fuel to the fire: Is Naruto just a completely immature kid who can't take the world's reality, despite the fact he wants to be a leader to a nation, and a rather unscrupulous one at that, if you consider what they are willing to do to keep themselves on top or because they're simply afraid. If you take all heroism and Messiah Prophecies, Naruto is just an immature brat who wants people's attention and got in a war he doesn't understand from beginning to end of it and wants to achieve peace, despite the fact such a thing would render the whole point of his life as a ninja worthless (No War = No Need for Super-Soldier Ninjas). Also, he is the weapon the village wanted: Completely Loyal, despite the fact few people like him, powerful, although not powerful or intelligent enough to turn on his masters, and has the talent for converting people to see things his way or The village's way. He does have a talent for getting people to follow what he says, no matter just how fairy tale-esque it all sounds. One could think of him as a Brainwashing Machine even!
Or... here's another crazy idea: Is Naruto simply a person with an enduring sense of fairness, honesty, and empathy that make it impossible for him to live knowing that injustice, nihilism, and self-serving agendas reign supreme throughout the ninja world? Is he actually someone in a very unique position where he has the conviction and enduring hope for the betterment of the world in face of adversity, doubt, cynicism, and outright sabotage? Is he a model example of the figure(s) necessary to enact dramatic change in society by being that anchor by which other people can hold onto and look to as a source of inspiration, strength, and guidance for their own self-fulfillment?
The Leaf Village! It can be A) A Nation of strong Ninja who believe in union and Peace, B) A Power-Hungry Nazi-esque Empire who wants to control the world and everyone in it, C) A Self-Centered and Bigot Nation who has so many people wanting to kill them it's hard to even think of them as innocent, D) A Village filled with Hippie-esque delusional fools. E) Mostly good people who have difficulty accepting those who are different or who they think might be a threat. The way they act and the things they believe has shades of all these. And most fanfic writers go for B, C and D options most of time if they're going for Dark Fics or just Naruto becoming independent.
The Uchiha Clan. Despite few individuals being shown from the clan, a number of fans interpret the clan as being filled with power-hungry bastards that deserved their deaths. Curiously, Mikoto (Sasuke's Mom) is usually exempted of this (Mostly because they think she's hot and is a popular pairing with Naruto), along with Itachi because of Draco in Leather Pants.
Alternatively, since Mikoto seemed to be friends with Kushina, it might suggest that there were at least some who wanted to remain loyal to the village, but in response to (perceived or actual) threat of being persecuted for their supposed role in the Nine-Tailed Fox's attack, they decided to rebel.
Power-hungry bastards, or the sad end result of generations of war wiping out all the most emotionally stable members of a clan Blessed with Suck by a powerset that combines the worst parts of Power Born of Madness and With Great Power Comes Great Insanity, combined with ninja paranoia about keeping bloodline powers proprietary limiting the outbreeding that could dilute their hereditary cases of Love Makes You Crazy and Evil? Or perhaps even a clan that got a rather short of the stick by getting massacred over the notion that every single member was somehow in part of the planned coup.
Fugaku Uchiha initially starts out as mainly concerned with his elder son's career in the ANBU, while viewing Sasuke as secondary at best, leading to a few different interpretations in and out of universe. Sasuke initially believes this is a clear-cut case of Parental Favoritism, with Itachi being held up as the model older brother. Fugaku's wife Mikoto argues that Fugaku, as head of the clan, has to think of the clan's well-being (which is why he's concerned with Itachi's troubling behavior), but as a father, is proud of and cares for Sasuke. In Itachi's Story, Itachi eventually comes to believe that Fugaku treats him as a tool, which may lead readers to believe that after Itachi's reliability comes into question, Fugaku started to see Sasuke as a replacement for Itachi.
Kabuto Yakushi, although this is probably on purpose: a Chronic Backstabbing Disorder who was waiting for the chance to kill Orochimaru himself for power when Sasuke did it for him, a man who saw Orochimaru as a god, went crazy at his death and integrated his remains into his own body, or a man who joined the first person who gave him some sympathy because he had nothing left to lose?
Is the Fourth Raikage an honorable, just leader who cares for his loved ones and is the right person to lead the alliance? Or is he hypocritical in seeking retribution for those who wrong him while forgetting his and his subordinates own misdeeds? And did he order the kidnapping of the three-year-old Hinata, was he trying to cover it up, or was he unaware of what one of his subordinates tried to do?
Jiraiya. Is he a man who stayed away for Naruto's own good while secretly helping him from behind the scenes? A lazy pervert who abandoned his own godson to peep on naked women and only connected with him because of an accident? Or does he secretly nurse a hatred for Naruto for being the cause of his beloved student Minato's death? Yet another interpretation is as a result of viewing himself a Failure Hero who only realized at the end of his life that he actually did some good by teaching Naruto, is that he didn't believe he could adequately help Naruto.
Kakashi Hatake is similar to Jiraiya. Is he a man who stayed away from Naruto to focus on Sasuke, a boy who was much like him at that age? Or is he a man with a guilt complex who abandoned his sensei's son because he secretly thinks he's responsible for the death's of all the important people in his life? Alternatively, he chooses to help Sasuke because he's in the most danger at that point (Gaara presents a danger to his life, while Orochimaru presents a danger to his integrity and moral character). Naruto was far less likely to get killed by Neji (who, at worst, considers him a loser who can be beaten easily) or go down a dark path like revenge.
Obito Uchiha.:
Is his hatred against the world just a tantrum after his crush died? Or did her death make him realize how unjust a world is when people need to be sacrificed for others happiness?
It's commonly seen that Naruto had clinical depression prior to becoming a ninja (or even that he still does but hides it well) due to his loneliness growing up. He also showed signs of a lack of self-care, such as how he only didn't pay attention to his milk's expiration date, and his signature food is easy-to-cook instant ramen.
Hiruzen Sarutobi. Stupid intriguer who has failed to resolve an obvious conflict by peace and has screwed up wherever possible? Or a talented but old ruler who could not retire in time, since one successor was killed, the second turned out to be a maniac, and the rest either fled or did not grow up yet?
Haruno Sakura. The Load whose overconfidence in her own abilities and obsession with Sasuke only makes things worse for her team on the battlefield? Or an out-of-her-depth ninja who is ill-matched with her team, often Locked Out of the Loop with a side of Poor Communication Kills, and the only one who took her teacher's words about teamwork seriously by specializing in an area specifically meant to keep her teammates alive? For that matter, is she truly weak and unmotivated? Or is she more the logical result of Kakashi putting absolutely no effort into teaching her, in either Jutsus or information?
which might indicate stalking. But he never once did anything that other people considered to be a red flag and worshipped the ground she walked on.