Good enough.
Yes!
This!
I agree with this completely. However, it is important to realize that hell exists and that the presumption of mercy is not safe ground to stand on.
This is very simple to answer. God sends no one to Hell. People send themselves there by their actions and choices here on earth. If her father knows what he is doing is wrong, chooses to do it anyway, then it is a good bet he will send himself there. We never PRESUME to know where people are going as we hope they will repent, but we can never be supportive of their actions or thier immoral choices.
The bolded part is absolutely correct and perhaps you might want to consider building off of it. God’s Laws are aimed to our benefit; it is because He loves us that He has set down certain rules for our well-being and happiness. These laws, when trespassed, work to our own hurt and even ruin - sometimes individually, sometimes collectively and often there is even a generational delay before the full force of the consequences are felt. God is Father in the supreme sense; He desires us to spend all eternity in absolute bliss; nonetheless, He has given man free-will and a choice: we can choose Him and His holy Will and everlasting happiness, or we can choose our own will; hence we pray, “Thy Will be done, Thy Kingdom come, on earth as it is in Heaven.” Sodomy, being totally contrary to our human nature, harms our nature: the Apostle tells us that it has very serious consequences in and of itself, because it is a perversion of nature. Your friend undoubtedly has a perfectly natural love for her father, and perhaps you should argue that it is out of love first for God and secondly for our neighbours that Roman Catholics insist on keeping God’s laws, which He Himself has given us for our well-being. We all have our crosses to carry in this life, and by those crosses we are made worthy of God and life everlasting. In learning to deny ourselves we also progress in love [charity] and virtue.