The universe is just one enormous 'Soul Filtering machine'

[SteveII]

I was not getting into why they did not sin--only countering an argument that God could create people in a "dimension" where they would not have chosen sin.
There are several possibilities. The doctrine of Sanctification is where a Christian is perfected in love, meaning that the heart is undivided in its love for God or that it loves nothing that conflicts with its love for God. It is reasonable to assume that being in the actual presence of God (or having access to the actual presence of God) has the effect of preventing a divided heart.

It didn't stop the Morning Star from having a divided heart.  What makes you think it will for the average human.

Angels were not made in the image of God. They have not been offered salvation/grace with the arrow being from sin to redemption. Apples and oranges.

In addition, whatever additional knowledge (promised in scattered versed throughout the NT) becomes known to us in heaven would likely have the effect of illuminating the consequence of sin and therefore eliminating the desire for it. Anyway, there are no logical problems with free will existing in heaven.

Knowledge has never been a palliative for sin.  And why couldn't God create these beings already imbued with this knowledge, or for that matter already in the presence of God.  Neither explanation offers a reason why God could not create beings who do not sin without going through the test.  Both can be applied at creation, if indeed they are the reason people in heaven do not sin.

No one has ever had perfect knowledge--so you can't really say that. 

I'm sure he could have. But you have just changed the starting ingredients for humans and it is not very clear how that would work. People being born with perfect knowledge? Never having to choose to love God.  Vast amounts of human development/experiences would not be possible (bravery, sacrifice, risk, fear, childhood, innocence, attaining knowledge, struggle, love, love lost, etc.). What you are talking about is a variation on the angel theme.