No. Superman comics are mainly about his heroic deeds, saving the world, and his battles against villains. They don't contain erotic stories as it goes against the positive and family - friendly image of Superman.
I don't really know. It could vary depending on the artistic style and the intentions of the comic's author. You might need to do some in-depth research or check with the comic's fan community for a clear answer.
Superman's sexuality has been explored in different ways in the comics. In some cases, he has been shown to have attractions beyond the traditional heterosexual norm, suggesting bisexuality.
Superman comics can vary in tone. Sometimes they take on darker elements to add depth and complexity to the character and his universe. However, the core of Superman's goodness and heroism still shines through, even in the darker moments.