Did I not quote this in my response?
He took a third of the "angels" with him.
Relevance?
He was a prisoner that once had a large group in his responsibility.
Relevance?
to reiterate, Satan sinned long ago, before Light was formed. That suggests that Heaven was created long before the universe. Jon 38:7
Would we think the abode of the Eternal God was Created?
Why is Satan here? We are only given one reason that suggest why anyone is here, held in darkness , awaiting judgement, Some sinners at God;s timing and conditions are offered pardons .
So are you saying you feel that Satan will receive a pardon? Has received one?
While I don't think we can be dogmatic as to why Satan is here, and I will reserve my own view for now, this has nothing to do with my response to the statements you made.
This is not a Biblical support for Satan being in charge nor does it support a view this universe is his prison. For that matter, we cannot dogmatically say that there are only two realities, Heaven and the Physical Universe, and this is doubtful because we would not place Hell in either Heaven nor in this current Universe. Yet Hell remains constant, and is said to already be in existence. We know it is, at least, in existence at the end of the Tribulation as the Antichrist and false prophet are cast into it. And that places Hell in a reality that will pass away.
The universe was not morally good/bad before Adam sinned but sin was here in the person of Satan and the fallen angels. The universe was and is a "place of the spiritually dead. that Jesus Himself said "let the dead bury their dead"
Mankind (the shared death of Christ) offers sinners redemption.
And that is irrelevant. Even if yo could show that when God said it was good that Satan was in the mix...Satan's sin is irrelevant to Adam's sin.
The universe was not "the place of the spiritually dead" when God created it. It is not until Adam sinned that we see a concept of spiritual death introduced to what is called of God...good.
Concerning your last statement, this too is interesting, so I wonder if you feel that mankind pre-existed his creation in Adam?
God bless.