Yes, it is quite popular. Many fans are intrigued by the idea of Supergirl and Batman in a romantic relationship. They enjoy exploring the dynamic between the two powerful characters from different backgrounds. The contrast between Supergirl's more idealistic and hopeful nature and Batman's darker, brooding persona makes for an interesting romantic concept in fanfiction.
Not exactly. Batman Begins is one interpretation of Batman's origin story, but it's not the definitive or only 'real' one. Different Batman stories and adaptations offer various takes.
Well, Batman's origin story often involves the trauma of witnessing his parents' murder. This event drove him to train and develop the skills and gadgets needed to become the Dark Knight.
The Batman character draws inspiration from a wide range of DC Comics. It's not tied to one particular comic. His traits and adventures are a combination of elements from various Batman-related publications.
No, Batman is not a novel. Batman is a well-known comic book character that has been adapted into various forms of media, including movies, TV shows, and video games, but not typically in the form of a novel.