Should the Muqtadi complete his attahiyyaat and then stand up or should he follow the Imaam

Q: To recite attahiyaat is waajib in the 1st sitting of 4 rakaats Salaah. If it is missed then sajdah sahw becomes waajib. Sometimes the Imaam recites the attahiyyaat very quickly and then stands up whilst many muqtadees have not finished their attahiyyaat. Should they follow the Imaam immediately or should they complete their attahiyyaat and then stand? 

Addicted to porn

Q: I am a married man with kids. However, I have been addicted to porn and cyber sex. My wife doesn't know, but i feel I cheat her and also commit a grave sin. I have tried to stop and repent many times but after a break of a month or so I start again. I feel hopeless and fear marriage break up and later on hell in my after life. Knowing I have made gunah-e-kabeera and that I have back tracked after repenting, is there hope for me? What should I do to cleanse myself and be hopeful of paradise?

Fatiha Sharif or Khatam Sharif

Q:

  1. Is it permissible to do Fatiha Sharif or Khatam Sharif (Recite some verses from the Qur'an like 4 Quls, Surah Fatiha, beginning verses of surah Baqra, etc) in the presence of food then convey the reward to all the deceased Muslims  and then make Dua) not thinking of Fatiha Sharif as compulsory. I was told that there is a hadith in Bukhari where the Prophet (Sallallahu Alayhi Wasallam) went to Anas (Radiyallhu Anhu's) house and food was presented in front of the Prophet (Sallallahu Alayhi Wasallam) who recited from the Qur'an and then made Dua. Is this true?
  2. Will it be permissible for a person to attend Fatiha Sharif or Khatam Sharif gatherings when one is invited, not thinking of Fatiha Sharif as compulsory ?

Custody of children

Q: What is the ruling regarding divorced parents and the custody of children? Two prominent muftis have said that although the children are 7 and 9 years old, yet they do not go to the father as the father is not capable of caring for children. It will not be forced upon the mother to let go of the children and also the fact that this is not a muslim country so the mother will not be forced to. However, when the children reach puberty, then they are given the choice to choose where they want to go. Is this true?

Masturbation whilst Fasting

Q: 

  1. Does masturbation nullify the fast?

  2. If it does nullify the fast, does this person have to stay without eating and drinking for the rest of the day?

  3. When he takes ghusl, will he just rinse his mouth and nose or will he gargle his mouth properly and put water properly in his nose?