Just based on the name, it sounds like it might involve inappropriate content. Fanfiction should generally follow ethical and appropriate standards, and if it's about sexual themes in a way that is not in line with good taste or proper values, then it's not appropriate.
I'm not sure specifically what 'sakura thinks sex fanfiction' is about as the name seems rather unclear and unrecognized in a general sense. It could potentially be some very niche or self - created fanfiction concept related to the idea of Sakura having certain thoughts about sex within the context of a particular fictional universe, but without more information it's hard to say exactly.
One possibility is that Naruto is initially confused by Sakura's assumption. He might be so focused on his goals, like becoming Hokage, that he hasn't really considered a romantic relationship with Sakura in that way. He could gently let her down, explaining that he values her as a friend and teammate but doesn't have those romantic feelings. This could lead to a bit of an awkward phase in their relationship, but they would likely work through it and return to their strong friendship.
Naruto might initially think it's a joke. He's used to Sakura being a bit unpredictable, but when he realizes she's serious, he could feel a bit pressured. He doesn't want to hurt her feelings, but he also doesn't want to lead her on. So he might try to avoid her for a while until he figures out how to handle the situation. He might also talk to his other friends, like Shikamaru, for advice on how to deal with Sakura's newfound belief.
Well, in such a fanfiction, there could be a lot of drama. Maybe Sakura starts acting really love - struck towards Naruto, while Naruto is completely oblivious at first. This could lead to some really comical misunderstandings, like Sakura bringing Naruto lunch every day thinking it's a couple - thing, but Naruto just thinks it's a friendly gesture.
Yes, it can be appropriate. Fanfiction allows fans to expand on the relationships between characters. In the case of Sasuke thinking about Sakura, it could be about his recognition of her strength, her loyalty, or her role in his life. It doesn't have to be sexualized. It could be a deep exploration of their connection from Sasuke's perspective, like how he values her as a teammate or a friend.
No, it is not appropriate. Fanfiction should generally adhere to ethical and moral standards. Writing about sexual content involving characters from a series is disrespectful to the original work and its intended audience, which may include children and those who do not wish to be exposed to such inappropriate content.
Well, it could make her more determined. She might feel guilty for not being able to protect him. So she could start training harder to avenge him or to make sure no one else she cares about dies.
One plot idea could be that Sakura and Naruto are assigned on a mission together. During the mission, Sakura keeps dropping hints about their 'relationship' which confuses Naruto. Eventually, Naruto realizes what Sakura thinks and he has to gently let her down, but this causes Sakura to be heartbroken and she becomes less effective in the mission.