What Am I Riddles

Question: I dig out tiny caves, and store gold and silver in them. I also build bridges of silver and make crowns of gold. They are the smallest you could imagine. Sooner or later everybody needs my help, yet many people are afraid to let me help them. Who am I?

Question: I'm in everybody but everybody still wants me.
I won't feed you but I'll feed the tree.

What am I?

Question: What is harder to catch the faster you run?

Question: A mirror for the famous, but informative to all.
I'll show you the world, but it may be a bit small.

What I am?

Question: I can be half without getting thinner.
I can shine with no fire.
I can be hidden but never taken.
I can stay dry while moving the ocean.

What am I?