Another aspect could be that the fanfiction delves into how Kushina's presence affects Naruto's relationships with others. For instance, his relationship with Sasuke could be different. With a strong maternal figure in his life, Naruto might be more stable emotionally and be able to approach Sasuke in a more understanding way, which could potentially change the whole dynamic of their rivalry and friendship.
One consequence could be Naruto's emotional breakdown. Since Kushina is his mother, her betrayal would be a huge blow to him psychologically. He might start to doubt himself and his place in the world.
Yes, there are many. Some fanfictions focus on the warm family moments, like Naruto's father Minato being excited and taking care of Kushina during her pregnancy. They might show how the village is also preparing for the arrival of the new baby, with friends and neighbors being supportive.
Perhaps Naruto finds a way to travel back in time and prevent Kushina's death in the first place. He could use his Sage Mode or some other special ability to manipulate time. And then, by changing the past, he effectively'revives' her in the present. In the Naruto universe, there are all kinds of crazy powers, so time - travel isn't completely out of the question.
Well, it's hard to say for sure. The concept of 'porn-like' is quite subjective. Some might consider certain novels with excessive sexual descriptions as such, but it depends on individual perspectives and cultural standards.
In many places, 18+ porn comics are considered illegal. This is because they can have a negative impact on society and violate moral and legal standards.