What Am I Riddles

Question: I join you in battle, fist clenched tight.
We pound three times with all our might.
If my rival decides he will sign for peace;
I'll crush him, and the fight will cease.
But if he lays his hand down flat;
I'll suffer defeat, that is that.

What am I?

Question: I am your most powerful weapon; I come before your eyes.. I help you seek the truth, yet I often give you lies. What am I?

Question: I'm the part of a bird that's not in the sky,
I can swim in the ocean and remain dry?

What am I?

Question: A five lettered word, I'm used to make bread.
Remove one letter and I'll burn you instead.
Remove two and do this to your stew.
Mix that around and a good drink we will brew.

Question: What is something that you always have with you but you always leave behind?