Jamaat Salaah and Imaamat

Q: In few mosques there are arrangements to offer prayer with jamat on 1st and/or 2nd floor along with the ground floor. I heard from some elder person that if the distance from one row (of jamat) to the subsequent row is greater than 2 row's size than prayer of the person of the subsequent row will not be valid. Hence if the roof's height of the ground floor is higher than the 2 row's size then the prayer of the person (offering prayer) in jamat on 1st floor will not be valid. Is this case true?

Q: My query is regarding the hadeeth of the child Sahaabi who performed salaah behind Nabi Sallaallahu alaihi wasallam and then went to his tribe and led the people in salaah.

1. Can the exact hadeeth be given with the references.

2. Is it permissible to use this hadeeth as a proof for a child being allowed to do imamat (albeit for taraweeh)

3. If possible, what is the fatwa of the A'imma Arba'a with regards to the above maslah.

I only ask this as recently in a musjid, naa baaligh children were allowed by the mutawalli of the musjid to lead the taraweeh salaah.

Q: I would like to find out all the Shar'ee laws pertaining to: - Imamat / leading a congregation in Salaah - Non Baaligh child making Imamat - Imam having a beard - Imam not following rules of tajweed. - Imam wearing his pants below his ankles. Please can I also have references for each of the queries.

Q:

1. Is it permissible for a person who is clean shaven (due to medical reasons - acne) to be Imaam of salaah?

2. If yes, would it still be permissible when there are Ulama and Huffaaz who would meet all requirements of an Imaam?

Q: When one misses a rakaat with Jamaat, as one stands up, do you start with Thana or Sura Faatiha.

Q: When namaz is being performed in congregation and I joined as muqtadi after third rakath and after Salam I will have to pray the due rakat, while performing my due rakath can other muqtadi join me which makes me imam to new muqtad?

Q: Can a husband lead his wife in namaz (congregation). If yes, what is procedure to do so?

Q: Can we perform pray/salaah behind any physically unfit Imam. For Example, he can't walk normally (his leg is broken and and he is operated). Please guide me to care extra in the salaah/Namaz.

Q: Can a nabaalig boy lead the taraweeh prayers?

Q: I have researched about it deeply and I can conclude that there are cases in which it is recommended by our religion to pray alone instead of attending congregational prayers such as when you feel that your life or assets are in danger, in state of fear of your death, etc. Hence my situation is that I love to pray in the masjid with all the people together but whenever I enter the masjid, I suspect everyone as a suicide bomber. During whole prayer I am not able to concentrate in my Salah, this happened more intense when I bring my kids with me at Juma or even daily prayers. During prayer I start to imagine blood and body parts on the carpet and during whole prayers my mind is busy in thinking that if it really happens, how I will save my kids? From where will we escape, etc. I feel much better praying alone in my house or more better in an empty masjid. My question is that in that case what should be the right thing to do?