More Riddles!

I can ruin cars and make swords crumble. Yet for all my power, I can't harm a club.

Two sisters, one dark, one fair. In twin towers dwelling. One from land and one from sea.

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

The poor have it, the rich need it. You'll die if you eat it.

When you need me you throw me away. When you don't need me you bring me back.

When you don't have me, you want me. But when you do have me, you want to give me away.

He got me in the forest. He sat down to seek me. He couldn't find me, so he took me home.

I have a name, but if you say it I'll disappear.

What will make the barrel lighter if you put it in a barrel?

I have lakes with no water, mountains with no stone, and forests with no trees.

What word is shorter when you add two letters on the end?