Is it permissible to mention the shortcomings of the deceased, such as a father, and would my dissatisfaction with him after his death incur Allah's wrath and deprive me of a comfortable life, especially if he was unjust, cruel, and stingy, and spent money on unlawful things, bearing in mind that I took care of him during his long illness and completed one full recitation of the Qur'an for him after his death?

If your hatred for your father is merely an internal feeling due to his injustice and his dereliction of God's rights, and it does not manifest in your actions through verbal abuse or disobedience, then there is no blame upon you, for a person is not held accountable for mere feelings.

However, if you speak ill of him and mention his faults in gatherings, this is impermissible and is considered a form of disobedience to him even after his death. He holds the sanctity of fatherhood and death, so do not mention him except with good. Strive to supplicate for him and maintain ties with his loved ones, and ask the rest of his family to forgive him.