Peace Lady Fatima,
Some of your points were already answered.
Jesus prayed to the Father because He didn't want to suffer a terrible death, so He begged the Father for another way to save our sins.
The Father made it known there was only one way to save us, through the crucifixion.
(6) If Pilate really wanted Jesus to die on the cross, why would he fix the crucifixion on a Friday evening knowing that the Jews would have to take him down before Sabbath and that such a little time on the cross was insufficient for him to die?
(17) Crucifixion was a slow death. It usually lasted several days. Death followed from exhaustion, inability to respire property as a result of being in an upright position or attacks by wild animals. Why did Jesus, who was a fit and healthy man used to walking the countryside for long distances, die so quickly in only a matter of a few hours?
Pilate feared Jesus and may not of wanted Him to die.
Jesus died anyways because He bore all of our sins.
I couldn't last a second on that cross!
( 8 ) Vinegar is often considered to have a stimulating effect, rather similar to smelling salts. Why, in Jesus’ case, did it suddenly lead to his death? (John 19:29)
Maybe it wasn't the reason.
9) How could an onlooker tell the difference between a man on the cross who had died and a man who had fainted (Mark 15:39) particularly when it is reported that it was dark at that time? (Mark 15:33, Matthew 27:45, Luke 23:44)
You can't faint when your crucified.
Your body will wake you up so that you can lift yourself to breath.
When someone "gives up" they die.
10) If Jesus was dead when he was removed from the cross, why did his body release blood and water, since blood does not flow at all from a dead body?(John 19:34)
Jesus was being moved around, this may have caused these to gush out.
Also, He was on a cross, so gravity would have caused stuff to pour from Him when He was pierced.
12)Crucifixion was meant to be an accursed death (Deuteronomy 21:23). If Jesus was crucified, did that mean he also suffered an accursed death?
Crucifiction is the worst way to die, so it's an accursed way to die.
(15)Why should Joseph of Arimathea and Nicodemus take so much trouble to recover the body of Jesus when this would have been the duty of the nearest relative?
Jesus's relatives were still in mourning.
(16) Why did Pilate agree to release the 'body' to Joseph of Arimathea (a known Jew and follower of Jesus) if he was not sympathetic to Jesus?
Pilate was sympathetic to Jesus.
I'll let someone else answer the rest, peace.