Answer:
I am a king but also a common device of measure. What am I?
Almost everyone needs it, asks for it, gives it. But almost nobody takes it.
What eight letter word has "kst" in middle, in the beginning and at the end?
I occur twice in eternity. And I'm always within sight.
How can a pants pocket be empty and still have something in it?
Dark, feathery, and popular in Baltimore and fantasy books.