I taste better than I can smell. Who am I?

Move three sticks of the spiral below to form a square.

What is the fastest way to double your money?

When I got four, I have it none.
When I got two, I have it some.
When I got none, I have it all.

What is it?

I look flat, but I am deep. Hidden realms I shelter. Lives I take, but the food I offer. At times I am beautiful. I can be calm, angry, and turbulent. I have no heart but offer pleasure as well as death. No man can own me, yet I encompass what all men must have. What am I?

A boy and his father are caught in a traffic accident, and the father dies. Immediately the boy is rushed to a hospital, suffering from injuries. But the attending surgeon at the hospital, upon seeing the boy, says 'I cannot operate. This boy is my son.' How is this situation explained?

Name a key which is hardest to turn.

The following question it puts forth you:

25 - 55 + (85 + 65) = ?

Then, you are told that even though you might think it's wrong, the correct answer is actually 5!

Whats your reaction to it? How can this be true?

What goes up but never comes down?

Decode below three cipher riddles:

26 L of the A
7 D of the W
1000 Y in a M