The unique characters of Ed, Ed and Deets are what make the fanfiction interesting. Writers can explore their relationships in different ways, creating new storylines that might not be in the original source. It's exciting to see how different authors interpret these characters and the situations they can be put in.
You can try fanfiction platforms like Archive of Our Own (AO3). It has a vast collection of fanfictions from various fandoms. Just use the search bar and type in 'Ed, Ed and Deets' and it might show relevant stories. Another option could be Fanfiction.net, although the tagging system there might require some more precise searching.
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.