An angel bonus panel comic could be a special or extra comic featuring angels. Maybe it offers additional storylines or behind-the-scenes looks related to angel characters.
Sure is. Anita Battle Angel has its roots in a comic. The comic's universe and concepts were translated into the film, with some creative adjustments to suit the cinematic medium.
One idea could be exploring the backstories of the angel friends in more detail. For example, you could write about how they first became angels and what their lives were like before joining the angelic realm. Another idea is to create a new adventure for them, like a quest to save a part of the celestial world that is in danger. Maybe they have to face a new kind of enemy or overcome a powerful curse.
Betty and Veronica are friends in the comic. Their friendship is depicted with various emotions and experiences, sometimes they get along great and other times they have misunderstandings, but it remains a friendship throughout.
It depends. Some web comic artists are friends and collaborate or support each other. But others might not have much interaction and just focus on their own work.