Thanks for your feedback!
Indeed, I do remember Elrond being in the Silmarillion at a certain point, but that's something only Tolkien fans could know. Also we would see Sauron, albeit perhaps on a different shape than the one at the Lord of The Rings.
The way Silmarillion is written makes it difficult to follow through (one can say it is written on a nearly Biblical fasion), so making it a movie seems really unlikely. We can only hope for it to become a reality someday.