The villagers of Konoha would be terrified. Naruto has always been their hero, and an insane Naruto would be like a nightmare come true. Some might want to exile him, while others, like Shikamaru, would try to come up with a plan to either subdue or cure Naruto, knowing that his power could cause a great deal of destruction if left unchecked.
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.
Sasuke would be deeply affected. He would probably feel guilty for not being there to save Naruto. At the same time, he would vow to uphold Naruto's ideals and make the ninja world a better place, as a way to honor his friend's sacrifice.
Sasuke would be extremely suspicious. He has always seen Naruto as his rival and a symbol of the village's hope. If Naruto starts acting like Pein, Sasuke would think it's some kind of trick at first. He might even be ready to fight Naruto to figure out what's really going on.
His friends would be horrified. Sasuke, for instance, who has known Naruto for a long time, would be shocked at this transformation. He might initially try to reason with Naruto, thinking that there's still some good left in him. But as Naruto's psychopathic behavior continues, Sasuke would be forced to consider him an enemy and take action to stop him if necessary.
His other friends like Shikamaru would try to analyze the situation. Shikamaru, being the intelligent one, would look for patterns in Naruto's 'insane' behavior. He might suspect it's a ruse, but he would also consider the possibility that Naruto is actually in trouble. So he would try to approach Naruto carefully and talk to him to find out the truth.
Sasuke would probably be both confused and a bit disgusted at first. He might see Naruto's new form as a sign of weakness. Sakura, on the other hand, would likely be more sympathetic and try to find a way to help Naruto. Kakashi would be calm as always and start to analyze the situation to figure out what caused the transformation.
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 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.
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.