Q 4:
If we are just two persons offering congregational Salah (Prayer), should we stand in one row or should the second person stand behind the first?
A:
The Sunnah in congregational Salah is that a Ma'mum (a person being led in Prayer) stands next to the Imam (leader of congregational Prayer) in the same row, if they are just two persons.
Ibn `Abbas (may Allah be pleased with him) narrated that
he stayed for one night at the house of his aunt
Maymunah. The Prophet (peace be upon him) woke up to offer optional night Salah, so he stood to his left, but he (peace be upon him) moved him to his right side.
(Part No. 8; Page No. 19)
Agreed upon by Al-Bukhari and Muslim.
May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.