Well, it depends on how you look at it. Technically, in official Kingdom Hearts content, Sora is a key character. But in the realm of fanfiction, many writers take the essence of Sora and create their own unique stories that are not part of the official canon but are still inspired by the Kingdom Hearts universe. So, in that sense, he can be considered as a major element in Kingdom Hearts fanfiction.
They are often portrayed as two souls with a deep connection. Sora is usually the more positive and heroic one, while Roxas has his own kind of edginess. Fanfictions might show them learning from each other.
I'm not entirely sure as I haven't read every detail of it. But generally, it likely involves Sora's adventures in the Kingdom Hearts universe, with battles against the forces of darkness and his journey to protect the different worlds.
Sora's real story in Kingdom Hearts is an epic tale. It begins with him living a normal life on his island until the Heartless attack. His Keyblade - wielding abilities set him on a path of discovery. He travels through worlds like Wonderland, Olympus Coliseum, etc. His relationships with other characters are crucial. For example, his friendship with Riku is tested as Riku is sometimes tempted by the dark side. Sora must constantly strive to become stronger, both physically and mentally, to overcome the challenges in his journey to save the worlds and the people he loves.
I really like 'Sora's Time - Travel Mishap'. It's a fun fanfiction where Sora somehow gets sent back in time. He has to deal with the consequences of changing the past while still trying to get back to his own time. It has some really cool interactions with younger versions of the characters we know. 'Sora's Hidden Power' is also a good read. It explores a new power that Sora discovers within himself, and how he uses it to fight against a new, powerful enemy.
Yes, in some fanfictions Sora might be depicted as afraid of X. Fanfiction writers often explore different aspects of characters' personalities, and fear can be an interesting trait to give to Sora. It could add depth to his character and create new storylines.
It's hard to say for sure. Kingdom Hearts 3 could be the end of Sora's story in this particular arc, but the series is known for its complex and evolving narrative, so there might be more to come in the future.
I'm not aware of any official gay stories about Sora in Kingdom Hearts that involve something called 'Tentacle Kingdom Hearts'. Kingdom Hearts is mainly a story about friendship, light, and dark, and while there are diverse interpretations among fans, this seems rather unorthodox and not part of the main narrative.
A fanfiction about Sora getting abused could also introduce new relationships. For example, if he is being abused by a group, there could be a character who comes to his rescue and forms a strong bond with him. This new relationship could then play an important role in future events in the fanfiction, either helping Sora get revenge or helping him heal from the abuse.
Donald and Goofy could still be his allies. Despite Sora being a vampire, they might see that he's still the same Sora at heart. Riku could also be an ally, as he has always been there for Sora in different situations. Maybe even some of the Disney characters, like Mickey Mouse, who is known for his kindness and understanding, would be willing to help Sora control his vampiric side and fight against any threats that come with it.