Various masaail of Jamaat Salaah and Imaamat

Q: There appears to be no practical requirement for a microphone to be used for certain Salaah in the Masjid, in particular Fajr where, unfortunately, the congregation is small. Therefore I have 5 specific questions:

1. Is it necessary from a Shar'ee perspective that the followers of the Imam need to hear the Qir'at of the Imam?

2. If the answer to the first question is in the negative, why are our Ulama using microphone for Salah?

3. What are the Shar'ee objections or requirements, if any, for using a microphone in Salah and

4. Even if the Jamat is large, is it not sufficient to use the method of citing people at intervals in different rows so that they recite the takbeer and everyone else can therefore come to know that the Imam has gone in to Ruku, Sajdah etc?

5. Finally, the use of the microphone also entails the Imam engaging in loud congregational Du'a after the Salah and/or announcement and/or Naseehah which then disturbs the Masbooq. Is this permissible? If not, why is it done by our own Deobandi Ulama?

Q: If one is travelling in a plane and wants to read salah with another brother in jamaat, in the limited space at the back of the plane would it be permissible due to space being limited:

1. The imam stands directly in front of a single muqtadi?
2. The imam stands almost next to muqtadi, just a few centimetres in front (due to space restrictions the ideal of one foot behind the imam cannot work)?
3. The imam stands on the right of the muqtadi, muqtadi behind imam one foot length?

Q: If a person led salaah intentionally without wudhu many years ago and now cannot tell each musalli because he does not know who they are
individually. How does one make up for this shameless act. The Fear of allah has entered him and it does not give him peace of mind until he knows that he is forgiven and he does not have to worry.

Q: Is it permissible for an Aalim who is appointed as Imam in a musjid to receive salary for Imamat whereas the five times salaah is obligatory for
the imam also and also it is a duty of a muslim who keeps the knowledge of fiqh and recites quran properly to lead the salah only for the sake of Allah without a salary?

Q: When the Imam says Sami Allah Huli man Hamidah, I try to say Rabbana Wa la kalhamd. But before I finish saying it, the imam says Allah Hu Akbar and goes into sajdah before I have finished saying Rabbana Wa la kalhamd. In this case, should I:

1. Stop saying  Rabbana Wa la kal hamd as soon as the Imaam says the takbir and goes into sajdah?
2. Continue to say Rabbana Wa la kalhamd while following the imam into sajdah?
3. Do not say Rabbana Wa la kalhamd at all knowing that I won't finish it in time before the imam goes into sajdah.

Q: When reading fardh salaah behind an Imam, does one have to read surah fatihah even if the Imam is reading surah fatihah?

Q: If I perform a fard salaat on my own and someone joins in,what is the procedure? My intention was not as an Imam. I am reading silently, do I continue aloud?

Q: After fajr and asar Salah, the Imaam saheb sits facing the muqtadi. Why?

Q: What is the method of making salam behind the Imaam in jamaat?

Q: If person A prays a fard prayer and Person B prays nafl prayer behind him, will Person A obtain the reward for praying in congregation (25/27 times the reward of praying alone), even though the person he is leading is only praying nafl?