A1) Qur’aan is the Masdar i.e. root word of ‘qa ra a’ ‘yaq ra u’ ..to Read / Recite.
A2) in Makkah
A3)^^ above question is un clear .. do u mean when it was revealed upon the prophet SAW or when it was revealed unto lau e mahfooz?
A4) Allah Almighty
A5) Hazrat Gibra’eel AS (the master/leader of All angels.