Answer:
Cut the wrong wire and it goes boom
My second is performed by my first, and it is thought a thief by the marks of my whole might be caught.
What gets broken if it’s not kept?
If you have me, you want to tell me. If you tell me, you don't have me.
Deep, deep, do they go. Spreading out as they go. Never needing any air. They are sometimes as fine as hair
you hold my tail while I fish for you
Easy
Animal
Difficult
Food
Funny
Kids
Logic
What am I?