Taubah and Repentance

Q: I made thread bracelets for a school project and my family. Since we’re from the subcontinent, amulets are common.

Some of my cousins asked for bracelets and I made them for their children to wear. I made for others but some of those people have moved out of the country and I am no longer in contact with them.

Also I had wandered into astrology and zodiac signs and stuff, discussing it with those around me including my classmates of which some are kaafirs and some Muslims. I did not know these were acts of shirk and most lasted from before to mid puberty. I don't know what to do so I can give charity on their behalf even if they are kaafirs since I'm not in touch with them.

Before I rarely prayed and fasted but now I know alhamdulillah I’m more practicing and have realized that the shirk I have spread. Is there a way to resolve the issue? I have no idea of their intentions and some are requesting bracelets but what should I say. 

Q: What happens if you make taubah and commit the same sin and this is then repeated 2 or 3 more times?

Q: If a person died and the other person did not get a chance to apologize to the dead person Can he go to the person's grave and ask for an apology? Will the dead person hear him from his grave?

Q: what is the difference between istighfaar and taubah? 

Q: How will one know if Allah Ta'ala accepted his repentance?

Q: I want to ask that in these days how can I repent to Allah almighty and how can I return to him? Also I disobey my mother and pray on and off not regularly, so how can I obey my mother and pray regurarly and read the Holy Quran?

Q: I’m a Muslim but I’ve committed zina and I’m ashamed of myself and want to kill myself right now. I’ve ruined my dunya and aakhirah. Will Allah forgive me??? I never ever want to do it again. How should I protect myself from this?

Q: A married man has done a mistake by having intercourse with another girl one time. He is feeling very ashamed of himself after that and is making taubah to Allah all the time. Will he be forgiven by Allah and what should he do to feel at ease? 

Q: Can an actress and singer go to jannah?

Q: Want to ask you that there is a person he or she self harms means he or she makes cuts on his or her body. Everytime he or she says that it's the last time but the next time he or she does the same thing again and again. What does islam says about this? Will Allah Ta'ala forgive? What will be the punishment for it?