I prick the hand that grasps too fast, my name grows shorter when I’m cast from one to many; count me twice, I lose a letter, not my spikes. What am I?

In a rush, you are of course! Just don't put me before the horse.

My first three is what you hail My last three is what traps fish In between is a container for waste

I spy the bird up in the tree, or watch a ship sail out at sea. I sit in hand, I point, I peer, distant details now appear near.

I hold back a river with a simple twist. I speak in drips when I forget my duty. I am touched every day, yet rarely thanked. What am I?