In this fanfiction, the Hidden Leaf Village as a whole might support Naruto. Gato is a threat not only to the Land of Waves but also could potentially be a problem for the Hidden Leaf in the future. So, the Hokage and the council might secretly back Naruto's actions. Additionally, some of the other young ninja from the Hidden Leaf like Shikamaru and Kiba might also support Naruto because they know Naruto is doing the right thing by getting rid of Gato.
The villagers of the Land of Waves would surely support Naruto. They have suffered a great deal under Gato's rule, so they would see Naruto as their savior. Also, Sasuke might support Naruto. Even though they have their differences, Sasuke would recognize the need to stop someone as evil as Gato.
Well, one possible plot could be that Gato has some new evil plan in the Land of Waves. Naruto, having grown stronger, decides he can't let Gato harm the innocent people there anymore. He uses his new jutsu and his quick thinking to outwit Gato's men first. Then, in a final showdown, Naruto unleashes a powerful Rasengan, directly hitting Gato and killing him, thus saving the Land of Waves from Gato's tyranny.
In a 'Naruto kills Gato' fanfiction, the plot could start with Gato's continued oppression in the Land of Waves. Naruto, having witnessed the suffering of the villagers, decides he's had enough. He uses his Shadow Clone Jutsu to surround Gato and his men. With a swift combination of Rasengan and his ninja skills, he takes Gato by surprise and defeats him, thus liberating the Land of Waves in a more direct and violent way compared to the original story.
There could be a power vacuum left by Adaly White's death. This might lead to different factions in the Gato base area vying for control. Naruto may then have to deal with the aftermath and ensure that a more just leadership takes over.
His friends like Sasuke would most likely support him. Sasuke, having walked a long path of redemption, would see Naruto's vision of an empire as a way to finally achieve the peace they both have been longing for.
I think some of the younger ninjas in the village would support Naruto. They look up to him as a role model. Also, those who have been helped by Naruto in the past, like the families of the villagers he saved. They would see that Naruto is fighting for what's right and would stand with him against the council. Additionally, some of the outcast ninjas who feel oppressed by the council's rules might also join Naruto.
His closest friends like Sasuke would most likely support him. Sasuke, who has also seen the dark side of the shinobi world, would understand Naruto's reasons for rebellion. Also, Sakura, who has always been by Naruto's side, would be there to support him. Shikamaru, with his intelligence, might also see the need for change and back Naruto up.
His friends like Sasuke, Sakura, and Kakashi would surely support him. They have been through a lot together and know Naruto's good heart and leadership potential.
It could be that Naruto has some sort of intel about Adaly White's weakness. He uses this knowledge to his advantage in the Gato base. He might first disable any guards or traps around Adaly White and then use his chakra - enhanced strength to land a fatal blow.
Well, it would be a very dark turn. Gato is a cruel and greedy character. Naruto might be forced to do bad things. Maybe he'd be used for Gato's illegal business. He could be made to fight against his friends in Konoha later on.
Sakura might support Naruto. She has always believed in Naruto and his ability to do the right thing. So when he becomes the leader of Root, she would see it as an opportunity for Naruto to bring positive change. She could offer her medical skills to help the Root members who may be injured during the transformation of the organization.