#1: Neji/Hinata is obviously canon.
Yes, there are people who claim this. No, I don't have a problem with the people who write it without claiming that it's canon. I like IchiRuki, so I'm in no position to bitch about people writing !canon relationships. I can, however, work myself into self-righteous fury over the ones who think it's canon!
a) The Hyuuga obviously inbreed.
This is not an unreasonable conclusion. However, bringing it up as canon support for NejiHina is unreasonable. Why? Because we are never shown in canon whether or not the Hyuuga inbreed. So stop using an assumption as if it were a fact. For all we know, the Hyuuga could just have a very demanding screening process for potential non-Hyuuga spouses.
b) It's not like they're brother and sister. They're just cousins, and Japan has no taboo against cousin incest.
This is the dumbest argument. Because it is like they're brother and sister. They grow up with the full awareness that they are related; their family ties are crucial to the way they relate. Hinata calls Neji niisan. Now, I'm aware that in Japanese niisan and neesan may be used to address people who are not, in fact, one's brother or sister, but using them still indicates a certain amount of sibling-like feeling. If Kishimoto wanted to show that Hinata and Neji don't view each other as family, he would have avoided such obvious indications of sibling-like feelings. And if you're going to argue genetics (they're just cousins, that's not really that much shared DNA, no inbreeding trouble there), which is just stupid because this is a comic not a biology textbook, they're actually half-siblings genetically. They share a quarter of their human DNA. That's a Bad Thing.
c) Neji is obviously smitten with her. It's so canon kawaii fluffy cute-chan!
And you see this where? Oh, right, he blushed at her once when they were small children and he was told to protect her. That means that now that he's not trying to kill her, he wants to make babies with her! WHAT. No, a romantic relationship between two people who've related to each other as family since a very young age is not kawaii fluffy cute-chan. It's twisty and political and complex and very, very uncanon.
#2: Sakura is a horrible person around Sasuke.
Kishimoto deliberately set up Sakura's early interactions with Sasuke--with all characters--to paint her as immature and obnoxious. It's just that because she's most intense around Sasuke, those particularly interactions stood out.
Unfortunately, as Sakura began to improve, Kishimoto...began to ignore her. He cut down on the number of scenes she had around Sasuke. We still saw them interact on occasion, though, and she was still most intense around Sasuke. She just wasn't an obnoxious little bitch anymore.
#3: Sakura had a very shallow crush on Sasuke and has now realized that she only ever loved him as a brother.
Oh, right. Because she clearly has much deeper feelings for Naruto, and they aren't at all brotherly. Because when she tells Sasuke I love you, we're meant to see it as her being a silly, deluded little girl despite all her improvement as a character by that point in the manga. She just had the vapors, that's all. Female characters and their initial love interests? We can't ever take them seriously, no matter how obvious the author tries to make it. No, it's only the male characters' initial feelings that ever matter. When Naruto said he thought she was a babe in chapter 3, that meant he'd love her romantically forever and ever no matter what happened throughout the rest of the series. When Sakura told Sasuke she loved him in chapter 181, that meant she was too stupid to see her true feelings, and only Naruto could show her the way!
#4: Sakura is completely over Sasuke, or on her way to it.
My immediate response to this is "what manga are you reading?" but here I'm going to Give Evidence.
a) Sasuke viciously rejected her in chapter 181, so of course she can't stay in love with him.
The people who claim this are the ones who not only hate Sasuke, but don't understand him at all and can't be bothered to try. They look at his behavior in 181 and compare it to the behavior of some imaginary chivalrous knight, or maybe Lee, or their idealized, super-romantic version of Naruto. Of course he comes up lacking there, because he's not Super-Romantic Naruto or Lee. But chapter 181 is every bit as important to Sasuke and Sakura's relationship as the SasuSaku fans make it out to be.
Why? Well, think about it. Since when is Sasuke polite? Since when does he go out of his way to protect people from harm? Only since Sakura. How many other people has he ever told Thank you? I haven't had the chance to reread the series in its entirety for a while, but I'm willing to bet the answer is Not Many. It's also, if I recall correctly, the first time in the series he uses the Sharingan's sleep-inducing ability. Prior to that, he always fights to kill or at least injure.
And what else was he supposed to do, take her with him to get corrupted and killed?
b) She's stopped caring about him during the timeskip.
She reveals that during the timeskip, she was constantly seeking information that would help her rescue Sasuke. And that's not even going into what she did to Sasori when he mentioned Orochimaru, since I haven't actually read that part yet. So in short: no.
#5: Sakura has feelings for Naruto now. The only way she could ever end up with Sasuke is if Naruto dies at the end.
No shit, I've actually seen someone argue that that's the only way she could wind up with Sasuke.
a) She blushes at Naruto and asks him if she looks more like a woman now.
Okay, point the first: the blush. Characters blush all the damn time in manga. Give me back my Naruto files and I'll go through them and pick out all the non-romantic blushes. Well, not really, but I will dig out a few of them.
But she asks him if she looks more like a woman now! That's total proof! Except...that's the sort of thing a girl asks her best friend who's been away for a few years, not her boyfriend. It isn't necessarily romantic.
b) She agrees to go on a date with him! Before he's even finished asking her!
I find it hilarious how the NaruSaku fans cite the 'before he's even finished asking her' thing as proof. Let's take a look at what actually happened.
"Hehe, so the two of us are on our own now, so is it a da--"
Sakura, glaring at him, "OK, but it's all your treat!"
If she were really starting to like him romantically, maybe she'd have blushed then, or stammered a bit with surprise, or at least been a little less blunt and annoyed. If you really push and twist it, you can see their early interactions after the timeskip as romantic, but it's not as cut-and-dried as the NaruSaku fans insist.
c) She cries for him.
I'll let twinbells handle this one.
#6: Lee is deeply, truly in love with Sakura.
You don't see this one around so much anymore, at least among people who've been actually reading the manga. But it still bears addressing. It goes back to the "male characters have more valid feelings than female characters" issue. He asks her for a date and swears to protect her. He never says he loves her--or even that he likes her. He clearly respects her; he must have had some sort of crush on her. But later information about his character paints a different picture, one that doesn't involve TWOO WUV. He's always seeking out impossible goals in order to better himself, and what better impossible goal than a pretty, popular girl who's very obviously nuts over another boy?
#7: Sakura ditched Ino all because of Sasuke.
This one is to some degree understandable, but it's also Wrong. In the flashbacks surrounding the InoSaku fight, we learn a lot more about their relationship--and about Sakura in general (and Ino, too, but it's not her I'm talking about here). Sakura, prior to the later events of the manga, defines herself based on other people. In Ino's case, she knew that Ino had helped her a lot, but she also knew that she was in Ino's shadow. That she needed to somehow gain some distance so that she could be her own person.
Needless to say, she didn't choose a great way to do it. It's not until later that she realizes that she can define herself as her own person without destroying her relationships. (She realizes eventually that she has to become her own person, not Sasuke's fangirl, but rather than pushing him away, she vows to protect him.) As much of a mistake as her actions in regards to Ino were, they weren't all about Sasuke. In fact, he was merely the catalyst.
Eh, there are more annoyances in the great pit that is Naruto fandom, but those are the ones that I had to get off my chest. Now I go back to writing fanfic! And eventually getting some stuff worked out on rosemush.