Restrangled... thank you for the welcome. I probably should have restricted my answer to the fact that some laws and practices were in place only because the people's hearts were hard. That was the only issue of this thread, and certainly the only issue I felt I had enough understanding to be able to answer.
I haven't studied much on the topic of sacrifice. Perhaps the story was influenced by the one who wrote it... (Moses, as some say)... or by the times of the one who wrote it... since the people at the time of the writing of this book were already sacrificing to God. Perhaps then, the true lesson of the Cain and Abel story would not be brought into confusion or misunderstood... that the man who did wrong was envious of the praise given to the man who did right in God's eyes, and that envy led to anger, and to sin and to murder.
Granted, sacrifice had to start somewhere, but there seems to be no command in the Bible to start sacrificing, or why God would need or want the sacrifices of animals, wines, vegetables in the first place.
As for Christ being a sacrifice? I think He came and died for many reasons. To teach us; to show us how to live by following his example; to fulfill prophecy so people would know that he was from God; to show us that he always obeys and loves God, even though he obviously did not want to suffer (praying that, 'if by God's will, this cup be taken away'); that he chose to lay down his life for us (he could have called upon his Father and an army of angels to save him); to show us that death had no power over him, that he in fact defeated death by rising from it and so would we; etc...
Big topic 
More important, at least to me, is to try and follow the example and teachings Jesus gave us.
T