Sorry, i didn't understood it, could you try to be more specific? Thanks.
Order of components in a loop makes no difference.

changing the water intake from bottom to top wont help the pump to push less water upwards? Cos if water goes from bottom to top through the rad there will be more water volume than if it goes up from tube and then goes down through rad to cpu... am i right?
It's a closed loop. The pump works equally hard no matter what you do. As much water as it pushes out of it's outlet automatically comes back into it's inlet.

You're missing the fundamentals of watercooling. http://www.overclockers.com/articles1088/