Of course I have read that he has been called an Angel of Light, but your post was about Adam and Eve and the serpent. I don't think satan would dare to appear in God's garden as an angel of light so again not relevant.....
I know some people that love the idea of serpents (not the religious one) Movies are made about them and books are written about them, but if your going to tell the story of Genesis, try sticking to scripture for your homily.
You are bringing in other scripture that is not relevant to the Genesis story....but if your a pastor, I hope those in your church are better at scripture than you...sorry, but that is jmho..
Young children in Sunday school are not told such false stories, nor are those in Catechism.
As a child I went to Sunday school in a Lutheran Church and had private instructions before marriage in the Catholic Faith..