I think her having a bunch of dogs is a symbolizes her dominance over everything, she's powerful and orders everyone around. Like how she made Denji simp over her, Denji will do literally anything for her and other people would to because of her power. She probably has a superiority complex so that's why she has all these dogs to make her feel superior and dominant. Which is the reason why she is the Dominance Devil.
That would be interesting, I'd like a story with a paradox. There's also the theory that if you went back in time and changed something, it creates an entirely new timeline. I think it would be cool if someone came up with a story where you could control timelines, or maybe a space-time magician that can travel to different timelines.