Given the strange and somewhat concerning - sounding nature of the term 'bakapervert', it is very likely not appropriate. Fanfic should generally adhere to ethical and moral standards, and this term gives off an impression of something that may violate those.
Most likely not. Since the term contains the word 'pervert', which has negative connotations related to inappropriate behavior or interests. Fan fiction is supposed to be a form of creative expression within the bounds of legality and good taste. And this term doesn't seem to align with those principles. Even if it's just a made - up or misused term, it still gives the sense of something improper.
No. Fanfic is a great way for fans to express their love for a particular fictional world or characters in a positive and creative way. However, 'bakapervert' in the term 'bakapervert fanfic' implies something deviant or inappropriate. In the world of fan - created content, we strive for content that is respectful, inclusive, and in line with general moral and ethical values, and this term doesn't seem to fit that bill.