Yes, I was thinking of that Job scripture also. I think you're right; Satan does have some sort of access to heaven. The scriptures I was thinking of have to do with inheriting the kingdom of heaven.
Garden of Eden was NOT heaven, it was simply a place that had everything a human may need and yes, God was there at ALL times. He is EVERYWHERE at ALL times.
No, I don't think it was heaven literally, but it virtually was. It was perfect; there was no sin; God was there. God is omnipresent, but He's not with us now like He was with Adam and Eve; there's a big difference there. He manifests His presence through the Holy Ghost post-fall, whereas He was there literally in the Garden.
I don't understand how you see God contradicting Himself.
Genesis 1: 28
And God blessed them, and God said unto them, Be fruitful, and multiply, and replenish the earth, and subdue it: and have dominion over the fish of the sea, and over the fowl of the air, and over every living thing that moveth upon the earth.
Genesis 2: 16-17
And the LORD God commanded the man, saying, Of every tree of the garden thou mayest freely eat: But of the tree of the knowledge of good and evil, thou shalt not eat of it: for in the day that thou eatest thereof thou shalt surely die.
Genesis 2: 25
And they were both naked, the man and his wife, and were not ashamed.
Genesis 3: 7
And the eyes of them both were opened, and they knew that they were naked; and they sewed fig leaves together, and made themselves aprons.
Genesis 4: 1
AND Adam knew Eve his wife; and she conceived, and bare Cain, and said, I have gotten a man from the LORD.
I think it's quite obvious. Adam and Eve, during their time in the Garden, did not bear children. They were innocent and ignorant of "knowing each other". A Book of Mormon verse states this well:
2 Nephi 2: 25
Adam fell that men might be; and men are, that they might have joy.
The two commandments were contrary to each other. Theoretically, Adam and Eve could have resisted the temptation and stayed in a state of perfect innocence, but God, with His foreknowledge, knew what they would choose, however long it took. This foreknowledge, however, was not a determining factor in their choice (in other words, they weren't forced to eat the fruit; it was their choice). Here is partly why the fall was necessary:
2 Nephi 2: 22-23
And now, behold, if Adam had not transgressed he would not have fallen, but he would have remained in the garden of Eden. And all things which were created must have remained in the same state in which they were after they were created; and they must have remained forever, and had no end. And they would have had no children; wherefore they would have remained in a state of innocence, having no joy, for they knew no misery; doing no good, for they knew no sin.
It's a little complex, but not overly so. This is why most Christians don't put too much thought into the fall. If you take it for face value then it's very difficult to see why God would allow us to be in this state in the first place. Jesus Christ saves us from our sins; that's not confusing at all. But why is that necessary in the first place? Why do we have to suffer and "know misery" if God is really omnipotent? If He loves us then why not just give us what we need so we can all go to heaven? If we are all His children, Him therefore loving us, then why does He allow some to fall from grace?
You should not take the fall for granted. If it didn't happen there would be no need for Christ and we would not be able to know His love. If we did not know sin then we would not know repentance. Some denominations blame Adam and Eve for their transgression, thinking that we would all still be happy and perfect with God; this is without foundation: The world was not meant to be left as the garden of Eden; or maybe I should say it was, but we were not meant to be like Adam and Eve. We would not have been in the garden; we would have been spirits without bodies; we "would have remained in a state of innocence, having no joy, for [we would have known] no misery", but even worse, without agency. The fall was a necessary part of the plan and integral in the gospel of Jesus Christ.