Oblivion, not eternal torment in hell fire, is the merciful end for the wicked. God is both good and severe, but His mercy endures forever.
The formula 'the coming of the Son of Man' is code for 'the Day of the Lord.' The formula does not refer to the fall of Jerusalem in 70 AD, but the days ahead.
Zephaniah has messages for the remnant of physical Israel, the house of David, and for the faithful remnant from the Israel of God.
Personified Jerusalem, whom God depicts as a grieving widow, blames others for her troubles while overlooking her own sins as the real cause of her sorrow.
The Seventh Trumpet is a call to assemble, a call to battle, and announces the arrival of a new ruler, Jesus Christ, separating the wheat from the tares.