What Am I Riddles

Question: A man shaves several times a day, yet he still has a beard.

Who is this man?

Question: Round like a dishpan and smaller than a bathtub.But the ocean can't fill it.What is it?

Question: With pointed fangs I sit and wait, with piercing force I serve out fate. Grabbing bloodless victims, proclaiming my might; physically joining with a single bite.What am I?

Question: It's hard to give up.Remove part of it and you still have a bit.Remove another part, but bit is still there.Remove another and it remains.What is it?

Question: When warm my house expands and when cold it contracts,
I am vital to a certain type of pact.

What am I?