In some fanfiction, Harry's abuse before Hogwarts is shown through his physical appearance. He may be depicted as undernourished, with bruises that he tries to hide. For example, he might always wear long - sleeved shirts to cover up the marks on his arms.
One possible answer could be that in some fanfictions, it might be Dumbledore who first notices the signs of abuse. He might see Harry's withdrawn behavior or the way he flinches at sudden movements, which are typical signs of an abused child. This could lead to Dumbledore taking immediate steps to remove Harry from that situation and bring him into the wizarding world earlier than in the original story.
The discovery of the abuse might make Harry more empathetic towards other students who have had difficult pasts at Hogwarts. He could become a sort of advocate for those who are bullied or mistreated. Also, it could affect his relationship with his teachers. Some teachers, when they learn of his past abuse, might be more lenient or offer more support, which in turn helps him grow and develop at Hogwarts.
Well, in many such fanfictions, it could be that Harry shows some unusual behavior like extreme shyness or fear around certain people. For example, he might flinch when an adult gets too close too quickly. This could be a sign that makes others start to suspect something is wrong. Another key event could be that he has unexplained injuries that he tries to hide, and when someone finally notices these, it sets off the chain of events towards uncovering the abuse.
One key element could be the exploration of Harry's early life traumas. Since he was abused, it might focus on how that affected his character development. For example, it could show his mistrust of adults or his fear of certain situations. Another element could be the discovery of his magic in the midst of this difficult situation. Maybe he unknowingly uses magic to protect himself from the abuse, which then draws the attention of the wizarding world.
It shows how the abuse affects Harry's behavior. He might be constantly on edge, always looking over his shoulder. This is a sign of the trauma he's endured. The fanfiction may also explore how he has trouble trusting people, which is a common result of trauma.
Yes, there are some out there. You can start by looking on fanfiction websites like Archive of Our Own or FanFiction.net. Just search for 'Harry is a Runemaster before Hogwarts' in their search bars and you'll likely find several stories to choose from.
In some versions of this fanfiction, it could be Neville. He also had a difficult family situation, so he might be more attuned to signs of distress in Harry. Maybe he notices Harry's worn - out clothes that are too big for him, which could be a sign of neglect, and then starts to piece together that something is wrong at the Dursleys'.
If there was a rivalry before Hogwarts, it could carry over and make their interactions at Hogwarts more tense. However, this could also lead to them pushing each other to be better. For example, in Quidditch, if Fleur is also a good flyer, Harry might strive to outperform her, which could improve his skills as a Seeker. And over time, this rivalry might turn into mutual respect.
The story would be drastically different. Without Harry, there's no Boy - Who - Lived to be the main antagonist to Voldemort. Hogwarts might not be the safe haven it was in the original series. Voldemort could target the school more directly, and the students would live in constant fear.