1) If God is all-knowing, why is prayer ever needed?
2) If God's love is unconditional, then why did he make hell?
3) If Adam and Eve only had sons, from where did their wives come?
4) If man is fallible, is it also possible his interpretations of religion are as well?
1) Prayer is not needed for God, but rather for ourselves. Think of it like this: if you have a friend and he knows everything about you, does that mean that you shouldn't still want to spend time with him? Trust me, I don't pray for God's sake, but rather for my own sake to come to know God.
2) God loves all of his children, however some chose with their own free will to not accept it. God would never force anyone to do anything that he or she does not want to do. If a person truly hates God and does not want to spend eternity with him, then God (who is all loving) does the loving thing by respecting his free will and not forcing him to spend eternity with him.
3) The story of Adam and Eve is not and was never intended to be interpreted literally. As I have said before, that account of the creation of the world was most likely written in Judah about 1020-930 BC. The author had no idea how the world was created, nor did he much care. Rather, he used the story as an allegory to show life as it should be and the origins of human weakness.
4) Yes. However, this is the doctrine of faith that is integral to religion. Of course the debate will go on and on about a "proof" or "disproof" of God. Pascal's wager is also not satisfying for many (although I cannot see why). This is a real consideration, even for the most religious of people. It was just discovered, for instance, that Mother Theresa struggled with this exact question much of her life in her own faith. This, however, did not stop her from living in a Christian lifestyle and placing trust in God.
Obviously, these answers are slight, but I thought I'd offer some answers.
Of course, these responses are not meant to generate hateful replies.