I appreciate the effort shown in all the back and forth about unprovable theories, but i would like to say that the word "sin" has been misused many times here and should be translated "imperfect" as it is a word that originally described an arrow missing its target.
So, breaking God's (or nature's) laws would obviously fit into "sin", but so would many other things - false assumptions that had negative consequences, lack of ability or drive to alleviate the evil that is obviously present in our world, etc.
The second example (regarding evil) is actually a much bigger problem than the creation of the evil itself. Have you ever thought about how few people there are that want to commit murder compared to the people who would rather let others just go ahead and live? The question here is not "how many hitlers does it take to start a holocaust", but rather, how many people who would rather not have innocents murdered participate, or just look the other way?
Of course all humans are "sinful", because they are all imperfect. Thus, they don't always do good, sometimes they do evil.
Here is where it gets sticky - I would say that God created humans imperfect or they would have had to choose not to "sin" and eat the apple, "causing" all future generations to be born into sin, also known as imperfection. Therefore, the root cause of the evil in the world is God's creation of mankind as imperfect beings.
(Thinking ahead: God's creation of an imperfect being is not cause for thinking that God is not perfect, most things that have any value beyond their base mechanical purpose are "perfectly" imperfect, and in that lies their beauty, power, and transcendence.)
Letting people exist in their imperfections, causing themselves and others incredible amounts of pain, is no more "evil" than creating gravity, or allowing humans to create "time", which results in all kinds of terrible events. It is just the way things are...
Anyone who complains about God should first point at themselves since a few people, even in their their imperfect state, have shown that we could do a lot to help alleviate this suffering, and most of us (including myself) don't do a whole heck of alot.
Then, let's try to imagine what the world would be like if it weren't this way. Well, we don't really have any idea what things would or could be like because our minds operate under the constraints of our existence. If we were not "sinful" we wouldn't have to be having a discussion about God's existence, because we would be perfectly able to see (or to not see) God, or at least gather enough information to come to some conclusion. (maybe faith is somehow more "perfect" than "knowledge" anyway)
conclusion-
Evil is something humans do. Humans are something God does.
I am sure God has an explanation for all this, but I am pretty sure it will end up being our own fault somehow.
Which could be why we'll have to spend the rest of eternity in heaven while God answers all our silly questions in a way which will satisfy our tiny little minds.
p.s. please don't ask about satan, i haven't figured that one out yet...