I know you get a lot of questions, but I'm hung up on this one.
In your answer about Satan's fall from grace, you conclude that Satan was in heaven: "Satan could at one time appear before God (Job 1:6; 2:1; I Kings 22:19-22); thus, he was in heaven." Couldn't he have appeared before God without being in heaven? I John 1:5 and Revelation 21:23-27 say God is light and in Him is no darkness at all. It also describes heaven as having no darkness. How could evil (darkness) have been before the throne of God? By definition, darkness is the absence of light.
"Micaiah said, "Therefore, hear the word of the LORD. I saw the LORD sitting on His throne, and all the host of heaven standing by Him on His right and on His left. The LORD said, 'Who will entice Ahab to go up and fall at Ramoth-gilead?' And one said this while another said that. Then a spirit came forward and stood before the LORD and said, 'I will entice him.' The LORD said to him, 'How?' And he said, 'I will go out and be a deceiving spirit in the mouth of all his prophets.' Then He said, 'You are to entice him and also prevail. Go and do so' Therefore look! The LORD has put a lying spirit in the mouth of all these prophets of yours, and the LORD has declared disaster against you."" (I Kings 22:19-23).
Notice that in Micaiah's description states that God was sitting on His throne with all the host of heaven before Him. Therefore, we are talking about an event that took place in heaven. One of the spirits present was said to be a lying spirit. Therefore, there was a time when evil was tolerated in heaven.
We also know that this changed. After Jesus came to earth and returned to heaven (Revelation 12:5), we read: "And there was war in heaven, Michael and his angels waging war with the dragon. The dragon and his angels waged war, and they were not strong enough, and there was no longer a place found for them in heaven. And the great dragon was thrown down, the serpent of old who is called the devil and Satan, who deceives the whole world; he was thrown down to the earth, and his angels were thrown down with him. Then I heard a loud voice in heaven, saying, "Now the salvation, and the power, and the kingdom of our God and the authority of His Christ have come, for the accuser of our brethren has been thrown down, he who accuses them before our God day and night" (Revelation 12:7-10).
Revelation 21 is a description of heaven after Satan and his followers are cast into hell.
God is righteous (I John 1:5). Just because we sin, it doesn't make God less righteous. Just because angels sinned, it doesn't make God less righteous. Just because we all, the good and the bad, must appear before God to be judged, our presence before God doesn't alter who He is.