What Am I Riddles

Question: I talk, but I do not speak my mind
I hear words, but I do not listen to thoughts
When I wake, all see me
When I sleep, all hear me
Many heads are on my shoulders
Many hands are at my feet
The strongest steel cannot break my visage
But the softest whisper can destroy me
The quietest whimper can be heard.

Question: I come in many different colors. I create boundaries to keep things concealed and safe. My best friend is a lock and I am also made of different materials as well. I love to travel: you can find me anywhere. What am I?

Question: Having one, means having something to follow. Once you question it, it means having none. People seek it, but some do and some don't find it. What is it?

Question: Walk on the living, they don't even mumble.
But walk on the dead, they mutter and grumble.

What are they?

Question: Paint me up to look real good,
Then take me to the shop to maintain under the hood.
Use a small brush to make no mistake,
Or just replace me with something fake.

What am I?