Sasuke would likely be conflicted. On one hand, he and Naruto have a deep bond, but on the other, Sasuke has his own ideas about justice. He might try to stop Naruto at first, reasoning with him. If that fails, he could be forced to choose a side, either to support Naruto's cause if he believes there's some merit to it, or oppose him to protect the shinobi world as he knows it.
Kakashi would be deeply troubled. He's seen Naruto grow up and has always believed in him. He would probably try to understand Naruto's reasons first. Kakashi would attempt to talk Naruto out of it, using his own experiences and their relationship as a teacher - student. If that didn't work, he'd have to face the difficult decision of whether to fight against Naruto, which would be a very painful choice for him.
The villagers of Konoha would be in shock. They've always seen Naruto as their hero, the one who saved them from Pain. But if he starts a war, they'd be divided. Some would still believe in Naruto and think he has a good reason, while others would feel betrayed. This would cause a lot of internal strife within the village, with different factions forming depending on their stance towards Naruto's actions.
Sasuke might be conflicted. He has his own complex relationship with Naruto. Part of him might understand Naruto's reasons for leaving, but he could also be angry that Naruto didn't confide in him. Sakura would be worried sick. She has always cared about Naruto, and his leaving would leave a big hole in the team. Kakashi, on the other hand, would be disappointed but also respect Naruto's decision if he thought it was for a noble cause.
Iruka - sensei would be very concerned. He's always been like a father figure to Naruto. He'd probably spend a lot of time with Naruto, sharing stories from Naruto's past when he was brave and encouraging him to find that courage again. Kakashi - sensei would be more analytical. He'd observe Naruto closely, trying to figure out if this is a mental block or something more sinister. And the other villagers might start to lose faith in Naruto as their hero, which would add more pressure on Naruto to overcome his fears.
Sakura would be heartbroken. She's always had feelings for Naruto, and seeing him insane would be a huge shock. She'd likely try to use her medical skills to find a cure for whatever is ailing Naruto's mind. She might also try to get help from Tsunade, hoping that the former Hokage's knowledge could save Naruto.
Sakura would be extremely angry. She's Ino's friend and rival, and she would not tolerate Naruto doing such a thing. She'd probably be the first to go looking for Ino and confront Naruto. Sasuke, on the other hand, might be more calculating. He'd try to figure out Naruto's motives first before taking any action.
The villagers would be in an uproar. Naruto is a hero to them, and the idea of him kidnapping Hinata would be shocking. Some might immediately assume the worst and call for his capture. However, those who know Naruto better, like Iruka - sensei, would try to understand the situation first. They would look for reasons behind Naruto's actions and try to find a way to resolve the issue without causing too much harm. Konohamaru, who looks up to Naruto, would be deeply confused and conflicted. He would want to believe that Naruto has a good reason, but at the same time, he would know that kidnapping is wrong.
For Hinata, it would be a crushing blow. She loved Naruto so much. She might withdraw into herself at first, overcome with grief. But then, she could find the strength within herself to carry on Naruto's legacy, especially for their son, Boruto (if in a post - Naruto - has - a - family scenario in the fanfiction). Shikamaru, being Naruto's friend, would feel a deep sense of loss. He would use his intelligence to try to figure out what led to Naruto's death and if there was any way to prevent it in hindsight. And the other members of the Leaf Village would be in a state of shock and mourning. Naruto was their hero, and his death would make them question their safety and future without him.
The other Konoha ninjas would be quite shocked. The Hokage, whoever it is at that time, would see Naruto's change as a potential threat to the village's stability. They would likely keep a close eye on him and try to figure out what caused this transformation. Meanwhile, the younger generation of ninjas who looked up to Naruto would be confused and disappointed. They expected Naruto to be their role model of a kind - hearted and positive ninja, not someone acting like the feared Madara.
Sakura would be devastated. She has always had deep feelings for Sasuke. She might initially be angry with Naruto, thinking that there could have been another way. But later, she might understand Naruto's difficult decision when she realizes the threat Sasuke posed.
Temari and Kankuro would probably be very protective. They've always been close to Gaara, and seeing him as a baby would bring out their nurturing sides. They'd do everything they could to keep him safe and find a way to turn him back. Naruto, on the other hand, would be shocked at first but then would see it as his duty to help. He has a strong sense of justice and friendship, and he wouldn't abandon Gaara in such a state.
The other members of Team 7 like Sai would be confused. Sai doesn't fully understand emotions like the others, but he would know that this is a bad situation. He would follow Sasuke and Kakashi's lead in trying to find Naruto and Sakura. Tsunade, as the Hokage, would have to make some tough decisions. She would probably send out search parties while also trying to keep the situation under wraps to prevent panic in the village. The other ninja in Konoha would be on high alert. They would be worried that Naruto's actions could be the start of a larger threat, either from within the village or from outside forces.