Himalaya Fair question. Re my suggestion that Jesus didn't have to die: haven't got a highbrow explanation of that. Put simply, if God is God, then he doesn't have to do anything because he is God.
Re what the sacrifice was for/to: going back to the OT, the Israelites used to offer sacrifices to God in atonement for their sins. As per my previous post, this carried on for a jolly long time and they kept on having to make sacrifices because they kept on sinning. Their covenant relationship with God was broken by sin, their sacrifice and repentance restored it. This process was repeated ad nauseum.
The point of Jesus was that because he was perfect, one sacrifice could take the place of all the others and didn't need to be repeated. The question of who the sacrifice was to is much more thorny because it gets into theology/beliefs about the trinity - three in one, one in three, Father, Son, Holy Spirit etc. - because it was a sacrifice of God's son - who was also God - to God himself. If I'm honest, thousands of books have been written on this by people much cleverer than me, it is complicated and I'm not sure I can provide an answer that makes loads of sense. But hey! What's faith without a bit of mystery.
BUT.... I'll give it a go and try and provide my opinion on your question about the fall at the same time.
I think there is a natural justice to things that comes from - and is - God. It is human nature for people who have been wronged to want to see payback to the people that have wronged them. An eye for an eye. Sacrifices across all cultures have developed for this reason and to try and keep in favour with whoever the people believe God is. From a historians perspective, war throughout history can be seen as two enemies perpetuating sacrifices against each other in the name of their God (and as we moved into more secular times post-enlightenment, in the name of their values). Again, in the Biblical accounts of battles, once a side had won, the dead of their enemies were offered as their sacrifice to their God (both by the Israelites and their enemies). So, humanity betrays a need for natural justice and I would argue that this comes from God. The problem is that this means that conflicts often go on for hundreds of years, simply because it becomes a case of an eye for an eye. The point in Jesus was that because he was a perfect sacrifice there is no need for any more. As per my previous posts, God was essentially saying to humanity "Look, there has now been one perfect sacrifice - all that is left is for you to repent of your sins and I will forgive youand, because this is the new order of things, this means that you must forgive the people who wrong you as well. Follow my lead - don't demand an eye for an eye, just forgive."
That's me putting words into God's mouth. Probably not a good thing to do but I'm hoping he won't mind.
So, the sacrifice wasn't so much to anyone, but for everyone.
This is really difficult to write down off the cuff on a messageboard and I actually need to go now so apologies for chipping off half-way through (seriously! - I hadn't even got to the fall yet - will try and do that later!)