Can I just ask why you make so many separate posts? Not a dig, just curious.
Interesting point about the insertion. Possible insertions aren't evaluated on how closely they fit with what we'd like to believe about God. It's down to issues like what versions the word crops up in, whether it's consistent with what we know about the writer's culture and use of language, whether it's the sort of thing that other parties would like to see in the text, whether it sticks out of the text in terms of theme. You could look at any old text in the same way. There are parts of the bible that clearly reflect the preoccupations of the people who compiled it. For instance, at one point they were compiling material in such a way that everyone would become aware that bad things happen to bad people and vice verca.
For a person of faith who is willing to look unflinchingly at the bible as a historical document, it's immediately necessary to acknowledge that it is at least partially man-made; a collaboration. If you are trying to prove the existence of God in this way or even know everything about God through this one book, it's problematic. There is not, as far as I'm aware, anything that would 'scientifically' prove the bible is the infallible word of God, although it does come across as a special text that can bear any amount of analysis. At the very least, its coming into being is a mysterious and rather miraculous thing that makes a compelling argument for the existence of God.
I disagree with the premise of the 'how are you different to me' question. Christians are instructed to live their lives completely differently - sacrificially and with love for the most vulnerable people in the world. For someone to turn aside from life as its usually lived is 'one thing' but such a huge thing that it's completely identifying, whether you have a faith or not.
Re the sacrifice of Isaac, this is not the only time in the bible when individuals seem to have a very unpleasant experience in order for a deeper point to be made. Take Hosea, who was told to marry a prostitute in order to depict God's forgiveness and commitment to a people who repeatedly turned away from their faith to other gods. It may be unpalatable but I don't see what that really has to do with the existence of God - he's not more likely to be real because we approve of him. There are many points of similarity between God in the old and new testaments. His hatred of sin doesn't change, nor does his emphasis on the creation of a society that is free from injustice. He is endlessly interested in forgiveness and compassion in both books, but not at the cost of tolerating suffering. However, in the old testament, he will wipe out a nation rather than tolerate a society that sexually and financially abused its most vulnerable citizens. In the new testament, the loathing of injustice is still there but the means of dealing with it are different.
The question about amnesty I will admit is slightly irritating because I've already said I dislike a nation being killed and obviously it is the fact that amnesty doesn't do this that I prefer. While it is absolutely true that the OT God and amnesty couldn't be more different for those instances, there are many other parts of the bible that dovetail with Amnesty's driving principles. I prefer the way Amnesty works in the way that I prefer pacifism over bombing a city.