What Am I Riddles

Question: I give advice to others,
yet I know nothing myself.
I am a hitchhiker destined to stay still.

Question: Round like a apple, deep like a cup, but all the kings horses can't pull it up.

What is it?

Question: I have heard of a something-or-other, growing in its nook, swelling and rising, pushing up its covering. Upon that boneless thing a cocky-minded young woman took a grip with her hands; with her apron a lord's daughter covered the tumescent thing.

What is it?

Question: For now I must stay under the man who made me,
but when he dies I'll be as powerful as he.
They will watch and listen to what I say,
then some of their money to me they'll pay.

Who am I?

Question: In a marble hall as white as milk, Lined with skin as soft as silk, Within a fountain crystal clear, A golden orb does appear, There are no doors to this stronghold, Yet thieves break in and steal the gold. What am I?