Is what happened to our father before his death—his refusal to listen to the Quran due to his rejection of the shaykhs, and his saying: "Satan wants to make us lose this world and the Hereafter"—along with his subsequent seeking of forgiveness, prayer, and utterance of the Shahada, and then his death from liver disease; considered a good ending? And is his unwillingness to listen to the Quran for the reason he mentioned considered something bad for him?

What you mentioned about your father are signs of goodness and a good ending. The illness mentioned is an abdominal disease, and it has been narrated in a Hadith (definition) that one who dies of an internal illness (al-mabtūn) is a martyr. So, your father's death from an internal ailment and his invoking of martyrdom at the end of his life are signs of a good ending.

As for his dislike of listening to certain reciters, claiming they were hypocrites (riya'), this was a mistake on his part. And his statement: "Indeed, Satan wants to corrupt a person's worldly life and his Hereafter" is a true statement, and his realization of that indicates the life of his heart with faith.

Filial piety (birr) does not cease with death. So, be diligent in showing piety to your father even after his death by praying for him, seeking forgiveness for him, fulfilling his pledges, maintaining the ties of kinship that are only maintained through them (your parents), and honoring their friends.