Yes, there might be some. Fanfiction platforms often have a wide variety of stories exploring different scenarios between characters. However, the idea of one character abusing another in fanfiction can be quite dark and may not be in line with the overall spirit of the original Naruto series. It's important to note that such content might also violate the terms of some fanfiction sites if it involves excessive violence or inappropriate themes.
There could be. Fanfiction writers can come up with all sorts of creative (and sometimes disturbing) ideas. But when it comes to 'Naruto abused by Sasuke' fanfictions, they are not as common as more positive or adventure - based ones. Most Naruto fanfictions tend to focus on friendship, teamwork, and the growth of the characters in a more positive light. Still, in the vast world of fanfiction, you might be able to find some, though they may not be easy to come by.