Answer:
You fill it and it empties, A metaphor for plenty, Depending on what half you see, It's either full or empty
What falls down but never gets hurt?
If you blow past your destination, you'll have to throw your car into this.
What has roots that nobody sees, and is taller than trees. Up, up it goes, and yet it never grows.
What is the ending of all that begins?
Though not a plant, has leaves. Though not a beast, has spine. Though many wouldn't need this thing, It's more valuable than wine.