What does this rebus riddle means ?

Below the four parts have been reorganised. The four partitions are exactly the same in both arrangements. Why is there a hole?

There is a square piece of paper with a hole that is denoted by the circle on the top right side in the given picture. You have to cut the paper in a manner that it forms two and only two separate pieces of paper and then rearrange the pieces in a manner that the holes come in the centre of the paper.

Solve the rebus riddle in the picture below.

I am a mother. However, I never give birth.

I am a father. However, I never nurse my children.

Wandering is not possible for me, but standing still happens occurs rarely.

Who am I?

How many times can you subtract the number 5 from 25?

A man is lying dead in a field where no one is around. His head is split open and his legs are disfigured. Near to him, there is an unopened package. No living organism can be found anywhere at the crime scene.

How did he die?

Solve the following series:
AZ, GT, MN, __, YB

When you say goodbye, I am what you need to tie.
I come as a couple and go wherever you run.
Who am I?

The following alphametic has only one solution. Can you find it?
ENLIST + SILENT + LISTEN = ANAGRAM

PS: You may start the number from 0.