Let me say, this is just one possible answer. There are a lot of different ways to attack the question at hand. Im going to hone in on a couple of specific things you said and give a simple answer from that stand point.
if all sovereign God
So if God is sovereign, that means he does what he wills, and is free to make his own choices, not only that, but he is in control over all things.
and then your 2nd assumption,
Sin is creation not acting/being as God intended
So if God is truly sovereign, things cant exactly go agains the way he intended can they? (not without his permission). at least if you really hold firmly to his absolute sovereignty over all things.
Maybe he intended free will, which places individual choices, whether good or bad, inside of his original intention.
So i think a better definition of sin is this example from the bible
1 john 3:4
4 Whoever commits sin also commits lawlessness, and sin is lawlessness.
This fits well with Satan, for the antichrist is called the "man of lawlessness"
Now, for his guilt, the law says in the 10 commandements, (exodus 20:13)
“You shall not murder.
Jesus says of the Devil, John 8:44 (Partial)
He was a murderer from the beginning
So from this simple setup, we see clearly Jesus affirming that Satan is guilty of transgressing the Law, which is sin.
i think this answers the title question,
Can the devil be considered guilty?
This scripture addresses the more nuanced question you posed, which is basically, "If God created something, and it becomes evil, can God still punish it, is it not Gods own fault? making the sinner innocent?"
This is where your belief in God being "Sovereign" is tested. Note Paul's words Romans 9:21-24New King James Version (NKJV)
21 Does not the potter have power over the clay, from the same lump to make one vessel for honor and another for dishonor?
22 What if God, wanting to show His wrath and to make His power known, endured with much longsuffering the vessels of wrath prepared for destruction, 23 and that He might make known the riches of His glory on the vessels of mercy, which He had prepared beforehand for glory,
this is not the easiest of the doctrines in the bible to accept, but its what it says. If God wants to punish the Devil. He will be Justified in his actions.