It's mainly because fan art often involves visual reinterpretation and can sometimes fall under fair use, while fan fiction typically involves extensive use of the original story and characters, which might infringe on copyright more easily.
Fan art slash fiction is a form of creative work within fan communities. Fan art refers to visual art created by fans, often inspired by existing works like movies, books, or TV shows. Slash fiction, on the other hand, is a type of fan - written fiction that typically involves romantic or sexual relationships between characters, often same - sex relationships. In the context of 'fan art slash fiction', it might be fan - created art related to slash fiction stories or characters in those stories.
It's possible. Fan art is often inspired by existing works. But if it has enough distinctiveness in terms of the art style, color choices, and the way the subject is presented, it can be copyrighted. But you have to be careful because if the fan art is too similar to the original in a way that it could be considered a copy rather than a creative interpretation, there might be issues. Legal advice is often a good idea when dealing with fan art and copyright.
I'm not entirely sure, but it's very likely. TvTropes is a comprehensive database for all kinds of fictional works. Given Konosuba's popularity, especially in the anime and light novel world, it would make sense for there to be a section about its visual novel on TvTropes. You could check by searching for 'Konosuba visual novel' on the TvTropes website.