Well, in such a fanfiction, the Naruto world would be a chaotic mess. Naruto as Kushina's father would mean the timeline of events related to the Uzumaki clan and Konoha would be all jumbled up. His relationship with Sasuke would also be affected. They were rivals because of their different family situations and goals. But with this new family setup, Naruto's motives and Sasuke's perception of him would be very different. And Naruto's status in the village might be completely different too, as his relation to Kushina would give him a different kind of standing in the Uzumaki - related matters in Konoha.
In such a fanfiction scenario, the village of Konoha would be affected too. Minato is a respected figure. His abandonment could cause a scandal. Naruto might not have the same level of protection from the village elders. This could lead to different power dynamics within the village. Maybe other ninja clans would try to take advantage of Naruto's situation. Also, Kushina's family might react in various ways, some might try to find Minato and some might focus on taking care of Kushina and Naruto.
Well, it would completely turn the story upside down. The family relationships are so crucial in Naruto. If Naruto were Kushina's grandfather, it would mean a whole new set of character dynamics. For example, Minato's relationship with Naruto would be extremely different. Instead of being his father, he would be some distant relative. And Naruto's connection to the Uzumaki clan would be much more complex and ancient. It could also change how Naruto obtains his powers. Maybe he would inherit some ancient Uzumaki abilities in a different way than in the original story.
Well, if Naruto got Kushina pregnant in a fanfiction, it would completely mess up the original timeline. Naruto was born to Kushina and Minato in the original story. If this were to happen out of the normal sequence, it could lead to all sorts of changes. For example, Naruto might not grow up as an orphan. He might have a very different upbringing with Kushina around. Also, the relationships he forms in the village could be different. His training with Jiraiya might not happen in the same way or at all, which would then impact how he develops as a ninja and his ability to face the various threats to the village.
Well, if Naruto were Sarada's father in fanfiction, it would completely change the family dynamics. For one, Sasuke's role would be very different. Sarada's character might develop different values and abilities, influenced by Naruto instead of Sasuke. The relationship between the Uchiha and Uzumaki clans would also take on a new form, perhaps leading to new alliances and political situations within the Hidden Leaf Village.
If Kushina were alive in Naruto fanfiction, it could change the story in many ways. For one, Naruto would grow up with a mother figure. He might not have faced so much loneliness and discrimination in the village as Kushina could have protected him. Also, Kushina was a powerful kunoichi. She could have trained Naruto herself, perhaps passing on unique Uzumaki techniques earlier. This could have made Naruto even stronger, more quickly.
Well, if Naruto was trained by Kushina in fanfiction, it could make him a lot more in - touch with his Uzumaki heritage from the start. He might learn unique Uzumaki jutsus earlier, like some powerful sealing techniques. Also, Kushina's feisty personality could be passed on more directly, making Naruto even more determined and head - strong in a different way than in the original story.
Well, it completely flips the original story. For starters, all the relationships get turned upside down. Naruto, being the father, would mean he was the one who made all the big decisions before Minato was born. It also changes the whole dynamic of how Minato would view Naruto. Instead of being a son looking up to his father, it would be a son trying to understand his father who is younger than him in the normal timeline. And Naruto's friends would now be his son's predecessors. It's a really wild concept that changes the Naruto universe we know in a big way.
Well, if Naruto is the father of Mikoto in the fanfiction, it could bring a whole new dynamic. Naruto is known for his strong will and his ability to make friends and change people's minds. As Mikoto's father, he might instill in her the same values. Also, considering Naruto's connection to the Nine - Tails, there could be some interesting plot twists. For example, Mikoto might have some sort of special ability related to the Nine - Tails or Naruto could have passed on some of his chakra to her, which would give her an edge in battles.
This fanfiction could also change the relationships with other characters. For example, if Kushina hates Minato, the Third Hokage might have to step in more often to mediate between them. And the other villagers might also take sides, creating a divided village atmosphere that is quite different from the united one in the original story.
If Naruto were killed by Kushina in a fanfiction, it would completely shatter the Naruto universe as we know it. Naruto is the main character, and his death would mean the end of his journey to become Hokage and bring peace. All the relationships he had built, like with Sasuke, Sakura, and his other friends, would be left in ruins. It would also mean that the prophecy about him might not be fulfilled, leading to a darker and more chaotic future for the Hidden Leaf Village.