She would be an awesome villain. I am also thinking of a Gargoyles Oc that is Oberon's sister named Hecate, due to the fact that Hecate appeared in Macabeth and was mistress over the three witches. I also named Oberon and Titania's children, Gloriana and Elbegast. Elbegast is more tolerant of humanity, while Gloriana is a typical arrogant fair folk.
Probably. Though Greg Weisman said that Oberon's father was a mortal human, so the idea any human could be as scary as Queen Mab would be implausible in the world of Gargoyles. If such a person did exist, they would probably give David Xanatos and his family nightmares.
Kinda wish we could have seen her in the show. Gargoyles was one of the best shows in the 90s. This is an awesome interpretation of the character. By the way, would you consider drawing some fanart of Oberon as well? He was one of my favorite characters on the show.