Why an Earth at All?

You wrote:

... if we still have Free Will in Heaven - but that we are perfected in some sense/way before we reach Heaven - then why couldn't God perfect us in this way before we reached Earth? I'm not trying to be flippant, but it's an important question to me. The fact that He did not leads me to believe that this life is some kind of test.

He could have ... He didn't. Why? I don't know.

We could extend that question ... why did God create the physical world at all? According to the Bible, God created both the physical world and the spiritual world. We live in the physical; angels and demons live in the spiritual. Why didn't he just stop with angels and demons? I have no idea whatever.

Life might very well be a test. Or it might be an opportunity. Recall the first question of the Westminster Larger Catechism:

• What is the chief and highest end of man?
• Man’s chief and highest end is to glorify God, and fully to enjoy him forever.

This is an aspect of my faith that I've only experienced in small snippets, for a brief period of time. But the effect was marvelous. There is a serenity and peaceful enjoyment that can be had, if we really wish to achieve it. But it seems to me that achieving it can't be accomplished while simultaneously doing things that are opposed to God's desire for us. It's like you and your daughter having a wonderful and satisfying relationship if she did things to intentionally offend you. It just couldn't be done.

I am sometimes helped when I spend some time reflecting on God's right to rule as God. It doesn't mean I stop resisting. But when I focus on God's sovereign right as Creator and Sustainer to be just that, I find it less difficult to accept -- for short periods of time -- that some things simply are as they are.