Azaan and Iqaamah

Q: Whilst making Du'a, a person hears the Azaan. Should he stop making Du'a and respond to the Azaan instead?

Q: When iqaamat is being given then we find that the muazzin sometime joins the words, eg hayya alasalah hayya alasalah, but should it be pronounced hayya alasalati hayya alasalah? Or are both fine (when combining). Similarly with hayya alalfalaah and qadqaamatissalaah?

Q: What are the general reprimands and warnings in the Ahaadith against general worldly chat whilst the Adhan is going on?

Q: Should one cease individual recitation of Qur'an and Dhikr whilst Adhan is taking place?

Q: Does the Azaan need to be repeated if half the Azaan was given out of the salaah time and half in the salaah time?

Q: Is it permissible to speak about Deen to a fellow Muslim in the Masjid whilst Adhaan is going on?

Q: If there are multiple azaans being heard at the same time, should one reply only to one or to all that one can hear clearly?

Q: What is the shariah rulings in light of (the Quraan and Hadiths) of appointing someone a مؤذن‎‎, (mu’aḏḏin) or someone is regularly call to
prayer (adhan) who is clean-shaven (without any beard)? To my little understanding a clean shaven person fasiq? Am I correct in my assertion?

Q: If a person did not repeat the words of the Azaan immediately after the muazzin but only remembered at the end of the azaan at the time when the muazzin reached Hayya Alal Falaah, can he repeat the words from the beginning of the azaan or he should only repeat the words of the muazzin from hayya alal falaah?

Q: What are the words for the iqamah? I have heard some people say that everything must be repeated twice and some say that most of the words are repeated once and only the ending is repeated twice.