Some fanfics may focus on the theme of self - discovery. Nozomi and Eli could be on a path of understanding themselves better, and their relationship helps in this process. There might also be a theme of mystery, like they are trying to solve a mystery within their idol group or in their personal lives, and their combined efforts bring them closer. Additionally, a theme of cultural exchange can be interesting, as they come from different backgrounds and share their cultures with each other through their relationship.
You can try some popular fanfic websites like Archive of Our Own (AO3). It has a large collection of fanfics from various fandoms, and there's a good chance you'll find nozomi x eli lemon fanfic there. Just use the search function and type in the relevant tags.
Not really. Eli might not be a typical ghost story. It could have elements that make you wonder, but it might not fit the traditional ghost story mold.
One common theme is friendship turning into something more. Since they are friends in the original series, fanfiction often explores the idea of their relationship evolving romantically.
There's not enough information given to really define who Eli is in the bearded stories. It might be a unique name given to a character in a local or niche set of tales. Maybe it's a name used by an amateur writer in their collection of bearded - themed stories.