(The following is an interesting take - one with which I don't agree totally, but one that is thought-provoking, nonetheless:)
I agree that Satan was a key player in the early stages of the Great Plan. In it, he seems to have realized that God’s plan had too much risk and pain involved, and so he devised changes that would ensure safety and security, in exchange for two things: some agency, and God’s throne. Agency and security cannot co-exist easily. In a realm where we would live in security and little agency, we cannot become as God is, and so we would require a replacement for Elohim that we could emulate. Lucifer becomes the example to follow in this instance.
Lucifer took with him those that feared risk, failure and pain. With the right press, God could be made to look like an evil rich guy running a sweat shop in Nicaragua.
Satan doesn’t push sins on us. He pushes choices upon us. Opposition. He provided the opposition and choice in the Great Council, and he does so now. The temptations and evils are already in place in the world without him. He just uses them as a catalyst to get people to follow his lead.
I truly believe that Satan, as with any of us who commits sinful and/or evil acts, has what he thinks are good intentions. He is trying to save us from a bad plan that promises to punish and enslave many (at least in his view). And if in attempting to save us (by drawing us away from God and towards him) we suffer some, it is God’s fault.
Comment #40 by Rameumpton on Mormonism's Satan and the Tree of Life, Part 1 - Ronan (By Common Consent)