I actually really like the concept because it lets the main character Have a reason for knowing how the tropes Happen and how they are most likely being exploited And the subtle indications of what happened in his other worldly adventure an interesting foreshadowing element
Personally I think the reason father Couldn't look at his daughter Wasn't because of her scars but because she looks so similar to her mother combined with Him feeling that he should have been able to protect her.
I think the demon who was the line survivor is the dad, it would explain why she is So secretive about the Identity of the father and why the father is not in the picture. It would also explain why he was so good at handling her demonifcation.