I think punk brings up a good point- what is the nature/structure of Heaven supposed to be? The book of Job implies that the Devil had the freedom to move about on both Earth and Heaven, and that God not only tolerated his presence, but was willing to engage in discussion with him. How does a spirit being enter/exit Heaven? What would it have been like for them to still be present there, when they were tainted by their rejection of God's authority?
This is the issue with many of these concepts. They're not fleshed out. The list of questions is endless. And so are the answers, because we're not wired to just accept the lack of detail. We have questions, and we need answers, and if the answers aren't forthcoming, we'll just make up our own. And, bam! You have a mythos.