I think I can basically agree with this. I know that God is not to blame for any evil, but if evil "exists only by our choice", then how does satan fit in? I would say that satan actively attacks us, fools and tricks us into doing things against our better selves. Maybe I'm splitting hairs on what you mean by "exists".
Lucifer, as all angels and men, is endowed by God with intellect. It is the intellect that allows us to make rational decisions which is free will. Your reason is free to choose God or to choose sin. So, the root of sin is in the free will. But without it, we would only be robots.
If you look at Genesis, the defining moment in serpant's delivery was the idea that even man can be "like gods." So, the driving force behind sin was a desire to be "like gods". If you look at Lucifer's reasons, it was the same desire."
The difference between us and satan is that fallen angels are condemned forever; we are not. There is no redemption for their rebellion and their fall from grace is permanent. Man, on the other hand, can be redeemed. But this redemption, just as our fall, must begin with a decision. Just as Adam decided to disobey, we must decide to obey. And just as Adam's fall would not have happened without God's punishment, our redemption cannot be possible without God's forgiveness.
Your reason is not driven by God. Your heart may be, but not your reason. That's why the crux of the faith (no pun intended here!) is love and not intellect.