Sukuna does die in the manga. The way it happens is quite dramatic and ties in with many other elements of the story, adding depth and tension to the overall narrative.
Maybe Tails hates fanfiction because it often goes against the original vision of the character. Fanfictions might portray him in ways that he doesn't like or in situations that are inconsistent with the official story.
Yuji doesn't end up getting executed. The manga creates interesting twists and turns that save him from such a fate. It's all part of the complex and engaging narrative.
Yuji is still kicking in the JJK manga. The plot has thrown many challenges his way, but death hasn't claimed him yet. Who knows what the future holds though!
In the manga, Sukuna doesn't possess all 20 fingers. There are specific story arcs and events where his finger count changes based on the plot developments.
In the manga, Sukuna does acquire all his fingers over the course of the story. This is a significant plot development that has major implications for the storyline and character dynamics.