Even in more liberal regions, there are still limits and regulations. These stories are not in line with the general social values of promoting a healthy and positive social environment, so they are usually restricted.
No. Writing such stories is often not appropriate as they involve sexual content which is not suitable for general public consumption and goes against moral and ethical norms in most contexts.
Yes, erotica sex novels can be considered a form of literature. They often explore themes of human sexuality, relationships, and desire in a fictional context. However, they are a controversial genre due to their explicit content.
The ethics of these stories are debatable. Some might argue that as long as they are clearly marked as erotica and are for consenting adult audiences, they are okay. But others may think that they objectify characters and promote a narrow view of sex.
Yes, they are likely only for adults. Given the nature of the content which is likely to involve sexual themes, it's not appropriate for minors. Society has norms and laws in place to protect the innocence of the young from such adult - oriented materials.
Yes, they often are. Female ejaculation stories are part of sexual literature that can be considered erotica as they deal with sexual topics and experiences. However, they are also a subject of study in sexology to understand female sexual response.