The Cullens might be shocked at first. If Bella's secret is something really unexpected like she has a hidden power, they will need some time to process it. They could be initially speechless.
Yes, it is quite common. Fanfiction writers often use this scenario to explore the relationship between Bella and the Cullens. It gives an opportunity to show the Cullens' caring side towards Bella.
In some fanfictions, the Cullens might hate Bella because of jealousy. Maybe other vampires are jealous of the attention she gets from Edward. Another reason could be that she brings too much danger to their family. Her presence could attract unwanted attention from other vampires or vampire hunters, which puts the Cullens at risk.
In some fanfiction, Bella might not forgive the Cullens because of a perceived betrayal. For example, if they hid something crucial from her again. It could also be due to them putting her in danger without her consent. Another reason could be a broken promise related to her transformation or her relationship with Edward.
Well, one possibility is that Naruto's energetic and determined nature would clash with the Cullens' more reserved vampire ways at first. Maybe he'd try to teach them some of his ninja skills, like how to move even more stealthily. He could also introduce them to new forms of combat, which would be interesting considering the Cullens' already impressive vampire abilities.
Well, perhaps Bella discovers that the Cullens have been lying to her all along about their true intentions. Maybe they were using her for some ulterior motive, like protecting their vampire secrets from other threats in a way that betrays her trust.
In the 'bella is kidnapped by the cullens fanfiction', one possibility is that Bella is kidnapped to be part of some vampire ritual. However, she refuses to cooperate at first. The Cullens then have to try and convince her that it's not as bad as it seems. This could involve showing her their more human - like qualities, like their love for art and music. As Bella spends more time with them, she may start to see them in a different light and even develop feelings for one of them.
Well, they could be interested in fanfiction as it might show new and creative storylines. The original Twilight story has its own plot, but fanfiction can take it in various directions. For example, fanfictions might explore what would happen if a Cullen fell in love with a different type of character. This novelty could attract the Cullens to read such stories.
They might be amused. After all, fanfiction often takes their own story and twists it in unexpected ways. It could be like looking at their lives from an outsider's, albeit a very creative outsider's, perspective.
Well, they could have mixed reactions. Some of them might be irritated if the fanfiction misrepresents them. For example, if it portrays Edward in a way that's completely against his character. But others like Alice might find it fun to see the wild ideas fans come up with, like new plotlines that involve their family in unexpected situations. She could be intrigued by the different futures the fanfictions seem to predict for them.