The scriptures read are Micah 5, Psalm 121 and Matthew 27.
Micah 5. The famous passage quoted in Matthew's nativity story is found here. It's about how the shepherd/leader of God's people will come out of Bethlehem. He will be a universal peacemaker.
The remnant of God's people will be exceptional. And God will end all war by ending those things people fight with and about.
Psalm 121. From Westminster Abbey, a lovely rendition of this psalm.
Matthew 27. Why did Judas change his mind? Did he not expect Jesus to be arrested? Was Judas a Zealot trying to force Jesus to start the revolution? Did he think Jesus had sold out in some way? It's impossible to know.
It's likely this crowd, gathered so early on the day of Preparation, when most Jews would be standing in line at the temple to get their lambs slaughtered, was made up largely of the Sanhedrin and members of Caiaphas' household. The idea is to get Jesus crucified and buried before the Sabbath/Passover. After the Sabbath was over it would be a fait acompli.
Crucifixion was meant to be both painful and humiliating. It was meant to discourage anyone else from trying the same things the executed person was accused of.
The robbers were likely revolutionaries captured with Barabbas.
The jeers aimed at Jesus echo the tempter's words in Matt 4:3,7.
The IVP Bible Background Commentary on the New Testament says the sour wine may not have been the painkiller that was offered to Jesus earlier but was given here to revive him and prolong his suffering.
Joseph of Arimathea must have had a lot of clout to get an audience with Pilate at such short notice and to get the body of Jesus, executed as a revolutionary, handed over to him, a non-relative. Most crucified criminals were put in a common grave, not a nice family tomb with a fine linen shroud.