Azaan and Iqaamah

Q: If a person has already performed fard salaah, and some people came to him and told him to say azaan for them so that they may perform their congregational prayer, is the azaan valid ?

Q: What should one say when replying to "Assalaatu khairun minan naum" in the fajr azaan?

Q: Is it wrong to say azaan is finished instead of azaan is completed?

Q: I would like to know what is the provision of using the loudspeakers in Islam. We have recently moved homes, and the mosque next to us loudly starts prayers at 4.45am, then 5am, then 5.30am and so on through the day, using the loudspeakers at maximum volume. Is this allowed according to the shariat? 

Q: Why is the Azan and iqama given when a baby is born?

Q: Can a woman give azaan in the musjid?

Q: What is the view of giving azaan in new born children's ears, is it proven in the Hadith?

Q: Can you please tell me when a baby is born, can you give the Azaan from a recorded video or a live video call or does it have to be in person?

Q: What is the mas'alah with regards to reading the Qur'an while the azaan is going on or to reply to the azaan. 

Q: Is doing dua after azan permissible in Islam?