God, Faith, The Bible  

I think I may be confused about all this talk about Christianity being the true religion and the Bible being Fact. I was raised Christian but now consider my self Agnostic.
I have many questions and I hope to find some enlightenment through intelligent discussions of this topic. I have come across many people on this site that are well versed in their faith as well as other faiths and I commend them for doing their homework because we are not hearing commits such as "because God said so". This is good. My reason for posting is to ask questions concerning the Christian God/Faith and the Bible.
So here we go:
1. Why do the different Christian faiths have different views of the same religion and which Christian view is right.
2. Why is there an Old Testiment and a new Testiment?Why are there several versions of the Bible ie: King james, The New King James, The New American Standard Bible etc.
3)Why is the God in the old Testiment Vengful and unforgiving but the New Testiment He/she is a kinder gentler
God? Why in the New Testiment is said that Jesus is God?
3. Which of the Testiments is more accurate? Which should be taken as the true book of God?
4. If God is a Perfect being and has infinate knowledge why then does He/She insist on Testing his children? For example: Adam and Eve Were alowed to live in the Garden of Eden and were told that they would not want for anything. There only rule was not to eat the apples from the Tree of Knowledge.
If God has infinate knowledge would He/She not know that Eve would choose to dis-obey that rule and convince Adam to so aswell?Then there is Abraham who was told by God to sacrifice his son to prove his faith. If God had no intention of letting Abraham fulfill this request why would God put Abraham through such a horrible event? I am pretty sure if i heard a voice claiming to be God and was told by this voice to sacrifice my son to prove faith in him I think I would check myself into the nearest mental health facility.
5.Why is it many Christian faiths accuse other religious faiths of being intolerent and advocating violence when many sects of Christianity do the same? Many Christian groups persacute gays and say that they are dis-obeying the word of God.Many Christian faiths accuse other faiths as being false and will go to Hell for this. Is that not intolerence? There have been many religious wars faught with the approval of the governemt such as the Crusades which is a clssic example of intolerence.
6. Why is that many Christians point out religious fantics and radicals in other faiths but not in there own?7.What makes Christianity more Valid then the teachings of Islam, Buddhism or the Church of Scientology?
By asking these questions I am certainly not suggesting that I think Christianity is a terrible faith as I realize that most of these questions can also be asked of other religions. I choose to focus on Christianity as that is where most of my knowledge lies. There is alot I would like to learn and try to understand.
Thanks to all who respond.