Once he realizes that Gaara is serious about the kidnapping, Naruto would start to plan his escape. He would use his ninja skills and his quick thinking. Naruto has a lot of experience in getting out of tough situations. He would look for any weaknesses in Gaara's defenses or in the place where he is being held. And while he's planning his escape, he would still be trying to reason with Gaara, hoping to resolve the situation without having to fight his friend.
At first, Naruto might be extremely shocked. He trusts Sakura as a teammate and friend, so being kidnapped by her would be completely unexpected. He would likely try to talk to her, asking her why she's doing this.
Naruto might initially be shocked and angry. He has a strong sense of justice and being kidnapped goes against everything he stands for. He would likely try to fight back immediately, using his basic ninja skills and his determination. For example, he could try to use his Shadow Clone Jutsu to create distractions and escape.
Naruto might initially be shocked and angry. He has always considered the Kyuubi as an enemy within him, and now being kidnapped by it is the worst - case scenario for him. He could try to fight back immediately, using whatever little chakra he can muster without relying on the Kyuubi's power.
Naruto might be initially confused. He is used to being friendly with everyone, and this sudden possessiveness from Fem Gaara could catch him off - guard. So he may just try to talk to her to understand why she is acting this way.
Naruto would probably be very confused at first. He trusts Sasuke, even if it's a Fem Sasuke in this fanfiction, and he wouldn't expect to be kidnapped by her. So, his initial reaction might be to try and talk to her, asking her why she's doing this.
Naruto would probably be angry at first. He's always been a free - spirited person, and being kidnapped by Sasuke, his friend - turned - rival, would surely make him mad. He'd likely try to fight back immediately, using his ninja skills and his never - give - up attitude.
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.
Sakura might be a bit surprised at first. She has always seen Naruto as a friend, but she would quickly come to support him. She knows how much Naruto values his relationships, and if he has found love with Gaara, she would be happy for him. Kakashi would be very accepting. He has always believed in Naruto's judgment and would see this as another step in Naruto's journey to change the ninja world. Shikamaru would probably be the one to think about all the political implications but in the end, he would also support it as he trusts Naruto.
Sasuke would be furious. He has a deep connection with Naruto, and he would immediately start looking for Naruto. He might go on a solo mission to find and rescue Naruto, using all his skills and powers. Sasuke would not rest until he got Naruto back safe.
Naruto could also feel a bit sad and lonely. He's used to being an outcast in the village, but he thought Team 7 would be different. So he might start to question himself. Maybe he'd start training on his own more, trying to become stronger so that they would have to notice him. And he might also try to find other friends outside of Team 7 to fill the void.