Rage comics can be copyrighted. If the creator of a specific rage comic has taken steps to register it for copyright protection, then it is copyrighted.
Well, that depends. Maybe you could provide more information like the plot, characters, or any unique features to determine if it's the Spartan Rage comic you're thinking of.
First, you need to understand Naruto's character. Think about what would really make him angry. Then, create a plot that revolves around that source of anger. For example, if it's the Akatsuki causing trouble, build on how Naruto would react in a rage.
The main benefit is enhanced creativity. It can make you think outside the box when it comes to your story ideas. For example, you might come up with a completely unique concept for a story that no one has thought of before.
I'm not entirely sure as I haven't read it specifically, but often in novels, there are protagonists who drive the story. There could be a young character who is dealing with the rage and trying to find a way through it.
One of the main themes is likely to be about the rage itself. It could explore the source of this intense emotion within the characters. Maybe it has to do with past traumas or difficult relationships.
A 'rage game novel' could be a novel that is related to rage games. Maybe it has a story set in the world of rage games, or it might be about the experiences of players in such games.