Taubah and Repentance

Q: How does one repent from insulting the Sahaabah? 

Q: If a person makes kufr by calling an average human being the son of god, how should he repent?

Q: If anyone commits adultery or fahashi with someone else's wife, but not sexual intercourse, how does he ask repent to Allah for this sin? Is this huqooq ul ibaad or not?

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?