One idea could be an OC who is a new ninja in the village and Kakashi becomes their mentor. The fanfic could explore their training sessions and how the OC grows under Kakashi's guidance.
Most likely not. Fanfics with such themes are often inappropriate and violate the general ethics and norms of the Naruto series. The Naruto series is mainly about friendship, growth, and ninja adventures, not such improper content.
Research the Naruto universe thoroughly. Know the rules, the other characters, and the overall atmosphere. When writing about Kakashi, stay true to his character. He's calm, intelligent, and has his own set of traumas. Incorporate your OC into this world in a believable way. You could also add some plot twists to keep the readers engaged, like the OC having a secret connection to an old enemy of Kakashi.
A better fanfic idea could be about Naruko and her training journey to become a powerful ninja. For example, she could go on a special mission with her friends to explore a new and dangerous land, and during this journey, they face various challenges and learn new jutsus.
It could be an original character created just for the fanfiction. Maybe a mysterious ninja woman who crossed paths with Kakashi during a mission and they had a brief but intense relationship.
One great sasuke oc pregnant fanfic might be one where the OC's relationship with Sasuke is deeply explored during her pregnancy. It could show how Sasuke, being a complex character, adjusts to the idea of becoming a father. Maybe he starts to become more protective and shows a softer side.
First, you need to develop your OC well. Decide on her personality, backstory, and how she met Sasuke. Then, think about how she reacts to being pregnant. Is she happy? Scared? When it comes to Sasuke, consider his character traits. He's usually a brooding type, so how does he handle the news? You can also add in some action or adventure elements related to the Naruto universe to make it more exciting.
Yes, there are many. Some might focus on her adventures in the Naruto world, perhaps teaming up with Kakashi on a mission. Others could explore her relationship with other characters like Naruto or Sasuke.
Maybe an OC from a different village who is sent on a mission with Kakashi. Their different backgrounds and skills create an interesting dynamic during the mission. For example, the OC could be a master of water jutsu and Kakashi has to adapt his combat style to work with them.