Answer:
Sharp and long, flag of the world. What is it?
Always wax, yet always wane: I melt, succumbed to the flame. Lighting darkness, with fate unblest, I soon devolve to shapeless mess.
Pirates put their booty in it.
I am black when I am clean and white when I am dirty?
I am the fountain from which no one can drink. For many I am considered a necessary link. Like gold to all I am sought for, but my continued death brings wealth for all to want more.
What do angels sing in the shower?