I think some power imbalance is logical from a couple of different aspects. Unless there are some (usually bad) circumstances, like the dad being a loser and/or very unlucky, or the daughter growing up in some very abusive environment, the father is generally more wealthy, more experienced and stronger.
This would be also the case in any relationship between an older man and a younger woman, and does not HAVE to be a problem, just one that would need to be approached carefully for the relationship to work.
In a setting where the daughter has been living in the same house as the father, there are additional issues like the daughter depending on the father for housing, food etc., but in the setting in Our Fate, this is of course avoided.
I think we have a different interpretation of the word "corruption". In my mind, it is definately something negative, by convincing, grooming or coercing the daughter into increasingly depraved acts, rather than the initiation in sex that every person simply must go through. I mean, I guess it is not uncommon for a girl to be a bit more reluctant when it comes to sex than a guy, moreso if the girl is young and inexperienced where the man is older and more experienced. That is fine, but although the guy can try to convince her, there is a line between what's appropriate and what not, and in case of a father-daughter relationship, this line is different than in relationship between two 20 year olds.
This game does it very well so far, in my opinion:
https://f95zone.to/threads/a-petal-among-thorns-ch-3-lockheart.87472/
"a journey of love, taboo and gray areas" sounds perfect to me!
But, to be perfectly clear, I am not against it if you were to put a darker corruption path in the game. I would just prefer a love path as well.
Yes, you can. It was one of the paths, only the potential love interest for Claire (I think his name was Lucas) was not so suitable. I would have liked a path where Claire and Anna would end up in a relationship, with the MC in a role of a good father.
What I particularly liked about Our Fate was the decision between getting romantically involved with Claire, or try to be a good father instead.
That also says a lot about the quality of Claire's character design, in my opinion. If she wasn't as likeable, or if the story wasn't as convincing, this decision would not be so difficult.