For follow-up discussion and general commentary on the topic. Comments are sorted chronologically.
Your assumption, that all was good is of course correct; but Satan had already been disavowed from his original state; and that was of the beautiful cherubim that was over the throne of GOD.
After Lucifer was booted out of heaven; his name was changed by GOD.
Notice: when the Sons Of God came before GOD in Job 1:6-12),
GOD called him Satan and ask a peculiar question, "whence comest thou Satan?"(the name Satan means adversary) and Lucifer means Son of the morning. If Satan had still been one of GODS reporting angels like the other "sons of GOD" then God wouldn't have had to ask him where he came from; for Satan was not honoring God any longer or was he part of heaven. GOD is OMNISCIENT, and of course new where Satan was at all times.).
Gen 3:1 says the serpent was more cunning than any beast of the field and he evidently could talk and possibly walk, for his penalty was that he had to crawl in the dust of the earth from that point on.
(Note:1Chronicles 21:1 Now Satan stood up against Israel and moved David to number Israel).
The same thing is happening here with King David as it happened in Genesis with the serpent. Satan didn't camouflage himself as the serpent, nor did he posess the serpent. Satan used the abilities of the serpent to convince Eve that he (Satan) had a better idea than to listen and obey God. Just like he tried to do in Isaiah 14:1-21 to the King of Babylon.
Isaiah saw through the manipulation of the King and addressed Satan head long. Satan's original name was Lucifer son of the morning. Isaiah said "How you are fallen from heaven; you who weakened the nations; you are cut down to the ground". For you said "I will ascend into heaven and I will exalt my throne above the stars of GOD. I WILL SIT ON THE MOUNT OF THE CONGREGATION, I WLL SIT ABOVE THE HEIGHTS OF THE CLOUDS, I WILL BE LIKE THE MOST HIGH GOD".
SOUNDS PRETTY MUCH LIKE A REVOLT TO ME, don't you think?
I might ADD that Jesus said in Mathew 13:11; "because it has been given to you to know the mysteries of the kingdom of heaven, but to them (unbelievers) it has not been given".