It depends on how the author writes it. If it's very graphic and violent, it might not be suitable for younger readers. But some authors can handle the dark theme in a more tasteful and less disturbing way.
I think it depends on how it's done. If it's written in a way that is more about exploring the psychological impact and the resilience of the character, and not just for shock value, it could be considered a valid form of fan - created content. But if it's gratuitous torture with no real purpose other than to be cruel, then it's not ethical. We should respect the integrity of the character and the feelings of the fans who care about her.
One possible motive could be jealousy. Bellatrix is extremely loyal to Voldemort, and Hermione is a very powerful and intelligent witch from the side opposing Voldemort. Bellatrix might see Hermione as a threat and also be jealous of the attention Hermione gets from Harry and Ron. So, she tortures Hermione to try and break her spirit and prove her own superiority.
Well, Bellatrix is a very complex and cruel character. In the fanfiction context, she might torture Draco to assert her dominance. She is a powerful and deranged Death Eater, and by torturing Draco, she can show that she is in control. Also, it could be related to her pure - blood mania. If she thinks Draco is not living up to the pure - blood standards in some way, she may take it upon herself to 'correct' him through torture.
Hermione's resilience can also be shown by her not breaking down easily. She might endure the pain and still taunt Bellatrix, showing that she is not afraid. This could be portrayed by her making sarcastic remarks despite the torture. Another way is that after the torture, she quickly recovers and is more determined than ever to fight back.
Hermione might resist by trying to escape. She could look for weaknesses in the place where she is being tortured. If there are any magical objects or elements around, she might try to use them to her advantage. Also, she could try to form an emotional bond with Bellatrix in a strange way. By appealing to Bellatrix's possible humanity or some shared experience within the wizarding world, she hopes to make Bellatrix stop the torture. However, this is a very risky move as Bellatrix is known for her cruelty.
Sure. There could be. For example, in some fanfictions, the 'torture' might be more of an emotional or mental kind. Bellatrix could use her intimidating presence and cruel words to torment Draco. This type of story can be interesting as it delves into the complex family dynamics within the Death Eater world. It can show how Draco tries to cope with such a difficult situation, perhaps by seeking help from unexpected allies like some of the Hogwarts students who oppose the Death Eaters.
Maybe introduce a deus ex machina element. For instance, just when it seems the torture is getting too much, a powerful magical creature appears and scares Bellatrix away. This would lighten the mood a bit and prevent the story from going into extremely dark territory. Also, the author could play with the idea of Hermione having some sort of pre - prepared magical protection that lessens the impact of the torture.
It makes the story's tone much darker. Hermione being tortured is a very cruel and disturbing event. It can heighten the sense of danger in the plot. For example, it might make Harry and Ron more determined to fight against the Death Eaters. It also shows the brutality of the villains like Bellatrix.