Well, there are indeed such fanfictions. The idea of Hermione being submissive in fanfiction can be a bit controversial as it's quite different from her canon personality. But in the world of fanfiction, creativity knows no bounds. Some stories might use this concept to show a different side of Hermione's character development, perhaps in an alternate universe or a relationship where she has to adapt in an unexpected way.
Yes, there is. Some authors explore this concept in their fanfictions. It's an interesting take as it goes against the typical perception of Hermione as a very independent and headstrong character. But it can also lead to some unique storylines. For example, in some fanfictions, this submissive side of Hermione might be a result of a spell or a new situation she finds herself in.