Yes, there are quite a few. You can find them on various fanfiction websites. Some explore their relationship in the context of the magical world, with unique plotlines that might involve them teaming up for a dangerous mission and developing feelings along the way.
One common theme is the exploration of forbidden love. Since they are from different generations in the wizarding world, there's an element of this relationship being something that others might not easily accept.
One great 'Harry Potter and Bill Weasley Fanfiction' is 'Bill Weasley's Journey'. It delves into Bill's adventures before he gets involved with the main events in the books. It shows his time as a curse - breaker in Egypt and how he acquired his knowledge of dark magic artifacts. Another interesting one is 'Bill and Harry's Bond'. This fic focuses on the relationship between Bill and Harry that is often overlooked in the original series. It explores how Bill becomes a sort of mentor to Harry in some aspects. There's also 'Bill Weasley: The Unseen Hero' which highlights Bill's role during the Battle of Hogwarts in a more detailed way than the books did.
One great Bill Weasley and Harry Potter fanfiction is 'The Unseen Bond'. It delves into the relationship between Bill and Harry outside of the main events in the books. It shows how Bill, with his worldly experience, offers unique advice to Harry. Another good one is 'Bill's Influence'. This fic focuses on how Bill's actions in the wizarding world have an indirect impact on Harry's journey. There's also 'Bill and Harry: A Different Perspective' which gives a fresh take on their interactions from the perspective of an overlooked bystander.
He might be developed as a protective figure. Given his family's connection to Harry, he could be extremely determined to keep Harry safe. This could lead to him being overprotective at times, causing some tension between him and Harry as Harry wants to prove himself. His protective side could also show his loyalty to his family and friends, which is a key trait of the Weasley family.
His character might become more nurturing. Bill is already a brave and capable wizard, but raising Harry would add a new layer of responsibility to him. He'd have to be more patient and understanding, as Harry has his own traumas from his past. He might also become more protective, like a father figure.
Well, it really depends on what you consider 'good'. There are likely some fanfictions with this theme, but the quality can vary greatly. Some might focus more on the emotional aspect of Harry's feelings towards Bill, while others could be more action - packed with this relationship as a side plot. You might also find that different authors have different interpretations of how such a relationship could develop within the magical world of Harry Potter.
Well, in some fanfiction, a writer might portray Bill Weasley as 'sucking' perhaps because they want to create a different or more complex character arc for him. Maybe they have a different view of his actions or relationships within the story. It could also be just a creative choice to add drama or conflict.
One possible fanfiction could be about Bill Weasley meeting his mate during his work at Gringotts. Maybe she is a half - blood witch who comes in to do some business. They lock eyes and there's an instant connection. Bill, with his long hair and cool demeanor, catches her attention right away. And she, with her unique charm, makes Bill forget all about the gold he was counting.
Well, in some fanfictions, Bill might use his knowledge of the wizarding world's secrets to protect Harry. For example, he could lead Harry through hidden passages to avoid Death Eaters. Bill has a lot of experience with different magical creatures and dark magic threats, so he could use that knowledge to keep Harry out of harm's way.