let me be clear:
SS-doesn't make sense- this he screwed up. There is no reason Sakura should have any feelings for Sasuke and no reason why she should have fallen in love with him.
NH-not exactly screwed up. NH does lack development, but this of course could change. Looking at this from a pure relationship perspective, it's natural for people to develop crushes on other people who embody what they lack. For example, Hinata was always shy and overlooked, Naruto always believed he could change who he was. That is why she developed a crush on him. He has always been nice to her[though oblivious and not reciprocating her feelings]. Now what Naruto considers a friendly act, Hinata could consider a romantic one, which could explain why it grew. Would I call it love, not really. In my opinion, it is more deep infatuation then love and is still one-sided. But it still lacks development for it to become mutual.
NS-This is not screwed up if he follows through, and in my opinion is well executed for a couple of reasons. First, Sakura grew to respect Naruto as a person and close friend in part 1, sometimes admiring his skill as a ninja and his kindness as a person. Part 2, she learns more about him personally. For example, before part 2 she did not know about the giant fox living inside of him. But the biggest reason why this is done well is because we have mutual moments of affection between Naruto and Sakura. For example, the eating scene. They have the foundation, and out of all the male characters, Naruto is the most stable as he has always had Sakura's back no matter what. This is also why it appeals to me the most because in the relationships I've been in, sure it can start with a crush, but it only grows stronger when the chemistry is right.
Now as for 540, the fact that she loves Sasuke does not make sense. However, considering the love is there, Sakura's emotional roller coaster has been realistic. In part 2, she is never confronted by Sasuke in his uber-evilness until the Land of Iron scene. This is where she first acknowledges that Sasuke has changed. Which means, that she had not considered her feelings for him wrong until that point. 540 makes sense, because of that fact. Sakura has only recently accepted her feelings as wrong. She knows that Sasuke is not a great man, and is starting to realize that her love for Sasuke is as Kishi put it Selfish.
She also realizes that Naruto really does love her, however this hit a hitch as well. Sakura has been rejected two times. Once by Sasuke when he said goodbye to her when he left to go with Orochimaru, and by Naruto at the Land of Iron. Now, after looking at Kishi's interview and the confession, it is clear that Sakura and Naruto have romantic feelings for each other[not too mention the hundreds of hints and NS moments] However, even though Naruto probably rejected her because she still had feelings for Sasuke, it's natural for her to be guarded about putting herself out there. On Naruto's end, he is going to feel hurt because he mistook Sakura's confession as her lying about her feelings for Sasuke, and her not considering that he would have gone after him promise or not. When she was only trying to ease his pain. This would explain why they haven't talked about the confession at all since they got back.
Hopefully she can get over this.
As for 615, Is it a NH moment? sure. But more in the friendly sense and not romantic sense in Naruto's case. It does make sense though for Hinata because she promised to hold his hand, and because it was Neji who sacrificed his life.
@Slextrem
Mistaking me for FrenchmyToast? Thanks a lot, I thought you, strider, and I were a team remember?


So much for that

..... You two do have VERY similar avatars....
