The determination of whether reading jinn stories is haram is complex. Different scholars and communities may have different views. Some might say it depends on the intent and the nature of the stories, while others might have a blanket prohibition.
In some Middle Eastern cultures, there are tales of jinn helping humans. For example, a poor family was on the verge of losing their home. One night, the mother saw a strange light in the corner of their room. The next day, she found a bag of gold. She believed it was the work of a benevolent jinn who took pity on their situation. Jinn in these stories can be both good and bad, and their actions often depend on how humans interact with them.
It's hard to say. Some might be based on superstition as there's no scientific proof of jinn. But many cultures have these stories passed down for generations, so there could be some elements of real experiences that got exaggerated over time.
I know of a story from a village. A farmer's crops were being mysteriously damaged every night. He set up traps for animals, but nothing was caught. One day, an old wise man in the village told him it could be the work of jinn. So the farmer left out some offerings like milk and bread near the fields. The next day, the damage stopped. It was believed that the jinn were satisfied with the offerings.
One real life jinn story I heard was from a man in the Middle East. He claimed that he often heard strange noises at night in his old family house. He thought it was the jinn. One night, he saw a shadowy figure that seemed to move through walls. He was so scared that he moved out soon after. He believed it was a jinn because in his culture, such unexplainable phenomena are often associated with jinn.
Writers can start by giving the characters a strong motivation related to Jinn. For example, if a character is seeking knowledge that only Jinn can provide, they could be desperate to find a way to summon her. They should also have distinct personalities. A character who is impulsive might approach Jinn without thinking of the consequences, while a more cautious character would plan every move carefully. Another aspect is backstory. A character with a tragic past might see Jinn as a last hope for redemption or revenge.
One popular storyline could be Jinn's origin story. Many fanfics explore how she came to be and what her true purpose was before being bound to the relic. Another might be Jinn interacting with characters in different scenarios that weren't shown in the original series, like her having a conversation with Weiss about the Schnee family legacy and how it relates to the greater story of Remnant. And some fanfics may focus on Jinn's power and how it could potentially be misused or used for good in different situations, for example, if a villain were to try and trick her into giving false information or if the heroes had to use her power in a very specific way to save the day.
In such fanfiction, the storylines could change significantly. Maybe Qui-Gon Jinn would have trained Anakin differently and influenced the fate of the Jedi Order.