Well, in some fanfictions, Cedric might use his magical skills to shield Harry from physical attacks. For example, he could cast protective spells like Protego Maxima to create a strong shield around Harry when they are in danger. Maybe in a situation where dark wizards are attacking, Cedric steps in front of Harry and uses his wand to fend off the spells aimed at Harry.
The contrast between Hermione's studious nature and Cedric's more popular and athletic image makes for an interesting dynamic in fanfiction. Writers can play with this contrast, showing how they might initially clash but then find common ground. Maybe Cedric helps Hermione come out of her shell in social situations, while Hermione helps Cedric with his studies in a more complex area of magic.
Cedric could be developed further by showing his past. Maybe he had a difficult childhood that made him so eager to prove himself with magic. This could add depth to his character and make his actions more understandable. For example, if he was bullied as a child for not being good at magic initially, it would explain his constant need to show off his skills now.
Yes, there are many non - smut fanfictions about Hermione and Cedric. You can search on popular fanfiction websites like Fanfiction.net or Archive of Our Own. Just use the search terms 'Hermione and Cedric' and then filter out the mature or smut - related stories.
Cedric Diggory's love story could be like this. There was a girl from his house. They first noticed each other during a Quidditch match. Cedric played amazingly, and she cheered for him louder than anyone. After the match, he came up to her to thank her. From that day on, they began to exchange little notes. Cedric would write her sweet messages, like how her smile made his day. Their relationship grew slowly but surely, with shared hugs during cold Hogwarts nights and stolen kisses in the secret corridors.
I'm not sure specifically as I haven't read this particular fanfic. It could be about Cedric having admiration or being a big fan of Edward in the context of the story world it's set in.
Again, without knowing the specific 'Cedric King story', it's hard to determine its significance. It could be significant to his family if it's a personal family story about his achievements or experiences.