The Red Heifer

What does the red heifer without spot or blemish signify? Why is the blood sprinkled seven times? Why in offering the heifer is the priest made unclean? How is this a covering for sin? Why wasn't it performed at the alter? How to we see the Old Testament in the New revealed? What does the red color of the heifer signify? Why couldn't even one hair be other than red? Why was the red heifer to be sacrificed 'once for all'? Can you add anything you do to salvation?