You can try websites like Archive of Our Own (AO3). It has a large collection of 'Black Butler' fanfictions, and you can search for ones specifically about Ciel and Sebastian with a kiss. Another option is Fanfiction.net, though AO3 generally has more comprehensive tagging systems to help you find what you're looking for.
I don't have specific information about who Miss Monochrome is in this context. She could be a unique character created for this particular 'never ending story'. Maybe she's a protagonist with some special characteristics.
Definitely not. The Black Butler series has a set of established themes such as the supernatural elements, the Victorian - era setting, and the complex character relationships. The idea of a 'leashed slave story' is completely foreign to the official canon and is likely a disturbing creation outside of the proper series. It would go against the overall tone and moral framework of the official work.
One plot idea could be that the kiss is a moment of realization for Ciel. Maybe he has been so focused on his revenge that he has overlooked his feelings for Elizabeth. The kiss makes him question his priorities and whether he can have a normal life with her. For example, he might start to consider giving up some of his more dangerous undertakings in the underworld to protect Elizabeth.
It could make Sebastian, Ciel's butler, more protective. He might see Elizabeth as a potential weakness for Ciel, or he could also view the relationship as something that could be used to further Ciel's goals. For example, if there are other noble families involved, Sebastian could manipulate the situation based on Ciel and Elizabeth's new - found closeness.
Yes, of course. Their unique personalities and relationships in the original work are the main sources of inspiration for fanfiction writers. Writers often base their stories on the existing characters' traits and the chemistry between them.
As far as I know, there are no official tickle - related events in a very direct sense. However, the characters do have moments of light - heartedness and playfulness that could potentially involve tickling in fan interpretations.
One tickle story could be when Sebastian might playfully tickle Ciel as a way to amuse him during a less tense moment. Maybe when Ciel is feeling a bit down and Sebastian uses tickling to cheer him up, making Ciel giggle despite his usually serious demeanor.
Yes, it is quite popular among some segments of the Black Butler fan community. Mpreg (male pregnancy) fanfiction often explores unique and creative storylines within the existing Black Butler universe. It allows fans to delve into different relationship dynamics and scenarios that might not be part of the original canon.