In the manga, Ultra Instinct is not achieved by Vegeta. The power-up is mainly associated with Goku's development and storyline.
Vegeta doesn't acquire Ultra Instinct in the manga. The focus on this ability is more centered around Goku and his training and battles.
Yes, he does. Vegeta achieves Ultra Instinct in the manga at a crucial point in the story.
Yes, he does. Goku achieves Ultra Instinct in the manga.
Goku definitely masters Ultra Instinct in the manga. This transformation gives him a huge boost in power and allows him to take on even stronger opponents.
Yes, he does. Goku achieves Ultra Instinct in the manga.
Yes, he did. Goku achieves mastery of Ultra Instinct in the manga after intense training and battles.
Yes, Goku has mastered Ultra Instinct in the manga.
Yes, eventually. As the story progresses, Goku gains more control and can use Ultra Instinct more freely.
There are indeed Naruto fanfictions where he has Ultra Instinct. Fanfiction writers like to experiment with different power combinations. By giving Naruto Ultra Instinct, they can create really exciting battle scenes. For example, Naruto could use Ultra Instinct to dodge attacks more effectively during a fight with a powerful enemy like Madara, adding a whole new dimension to the story.
Not as far as I know. Ultra Instinct Goku is pretty much a force to be reckoned with and hasn't been beaten in the manga.
Not that I know of. Ultra Instinct Goku is a pretty powerful form and it's rare for anyone to outright defeat him in the manga.