I’m sorry - I still don’t follow your reasoning. Just because God created Lucifer does not make the devil present at creation.
Trees are used time and again as symbols through out the volume of the Book. The 'tree of the knowledge of good and evil' was allowed in the Garden of Eden. Right along side the 'tree of life' which is symbolic of Christ. The tree of the knowledge of good and evil is the devil and until Christ banished him, the devil had free access to go to and fro on this earth. Never ever in a flesh body, and when Lucifer rebelled he was sentenced to death. Along with a numbered of angels/souls that followed the devil at the rebellion.
Up until the words 'tree of the knowledge of good and evil were recorded, everything except for Genesis 1:2 was described as 'good'. Now consider where did this knowledge of good and evil come from. God sure did not create the evil, but yet it existed. Planted throughout the rest of the WORD, even stated by Christ Himself explains who this 'tree of the knowledge of good and evil represents.