Spending ill-gotten money and singling out a son with gifts

Q: Fifty years ago my father traveled to Jeddah to work as many other people did. As Allah (Exalted be He) willed, my father worked in a house for a director of a usurious bank. My father continued working as such until his employer gave him a job in the bank. Thus, my father has been working in that bank with the director for thirty-five years. Even though my father is illiterate, he has been able to accumulate a great deal of wealth that enabled him to bring us up in the best way. We would eat, dress, and travel from that money until I reached twenty-five years of age. However, I am a righteous young man, all praise be to Allah Alone. I truly know Allah (Exalted be He) and fear His Punishment, and I know the dangers of Riba (usury/interest) both in this world and in the Hereafter. Even though my father gave me a flat as a gift that belongs to a building he owns on the occasion of my marriage and opened a foundation for me in one of his business firms because I am his eldest son, I am not satisfied with all of that. This is because I believe that the reward of Allah (Exalted be He) is much better and more lasting. So, please answer (Part No. 14; Page No. 74) my questions separately: 1- Is my father's money considered Haram (Unlawful) even though he worked in the bank buying and selling real estate? 2- Do I have to pay back all the money that my father spent on me during the past years? 3- Should I live in the flat that he gave me and work in his firm? I do not use any of the foregoing, or pay him rent. 4- Is there a valid Tawbah (repentance) that my father can do bearing in mind that he performs the Salah (Prayer), gives Sadaqah (voluntary charity), is dutiful to his parents, and remembers Allah (Exalted be He)? However, he does not know the dangers of Riba. 5- Do the actions of my father fall under the renowned Hadith of the Messenger (peace be upon him) that curses those who deal in Riba? 6- What does my father have to do so that Allah (Exalted be He) will accept the Tawbah of my father; especially that he has already retired? What should I do so that my father's sins may be expiated? 7- Should I disobey my father for the sake of obtaining the Pleasure of Allah (Exalted be He)?