1. The "firmament" as the KJV Bible calls it is called an "expanse" in modern translations or atmosphere where birds later flew "upon the face of the expanse of the heavens". (Genesis 1:20) The Bible says "There were heavens from of old and an earth standing compactly out of water and in the midst of water by the word of God; and by those [means] the world of that time suffered destruction when it was deluged with water. (2 Peter 3:5,6) So the waters above the expanse were suspended and created a greenhouse effect on earth. Thus Adam and Eve could walk about without clothes in comfort. These waters above the expanse fell during the Deluge.
2. The Bible speaks about Jehovah as the One perfect in knowledge. (Job 37:16)
As the Source of all life, God's wisdom is beyond our understanding. He is "the One who made the heaven and the earth and the sea and all the things in them." (Acts 4:24) So God is the source of all accurate knowledge.
God decides what is good or bad. He does not need man for this. "Who teaches him in the path of justice, or teaches him knowledge, or makes him know the very way of real understanding? Look! The nations are as a drop from a bucket; and as the film of dust on the scales they have been accounted." (Isaiah 40:12-15)
3. Yes, chapter two expands upon the account in chapter one. It is not a separate account.