"Created himself to kill himself to prove a point to himself? Or to save mankind wich he could have done without getting born in the human world and get crucified?"
God sent his only Son to us to be crucified for two reasons:
1. To fulfill the prophecies of the Old Testament.
2. To make a perfect covenant with mankind.
God wasn't trying to prove a point by becoming man and subsequently being killed. He did so in order that we might better understand His infinite compassion for us. Also, sacrifices were used by the Jews to relieve the people of their sins. Christ was therefore a perfect sacrifice that allowed all of mankind to be forgiven. His death and resurrection was a labor of Love.
"An other thing, why would it take a supernatural, omnipotent being six days to do anything? And why would he need an entire day to rest after he is done?"
We've already discussed this. Stop reading Genesis literally. It didn't take six days to create the Universe. Since the world hadn't been created yet, how would there even be a concept of time? Genesis merely illustrated the steps that creation followed using the concept of "days" as a metaphor so that the people could better understand. Obviously this didn't work for everyone.
"And why is the sins and the ten commandments, exactly thoose sins and ten commandments? It could have been completely different things."
It could have, but it's not. What's your point?
God gave us ten commandments and a specific list of sins because "right" and "wrong" are not relative, they are absolute. He was imparting this knowledge to us so that we may choose whether we will be good or bad.
"And why would God create DNA, fossils, retroviral DNA and making animals with similiar DNA? And why does all animals look just like they do? Why is the world a small rock in a big empty space?"
Because if it wasn't this way, it would have to be another way and you would still be asking this question. Why make it any way? God made it this way because this way works. That's the beauty of it.
"And why is god keeping track on everything we do, doesn't he have anything better to do? And when he already knows what we are going to do?"
You're putting God in a human position. He isn't sitting in Heaven with a ledger book propped up, making a list of who's been naughty and who's been nice. That's Limbo (I mean, Santa Claus). God is all knowing, so he already knows what we've done and what we're going to do. We cannot give God a concept of time because He is in all places and all times at once.
"Our Constitutional rights are like precious diamonds -- and like diamonds, if we want to keep them precious, we have to keep them scarce." -- Stephen Colbert
"The absence of evidence is not the evidence of absence." -- Jules, "Pulp Fiction"
"If I have seen a little further it is by standing on the shoulders of Giants." -- Sir Isaac Newton
"Why is everyone so fucking stupid?" -- Kim Jong Il, "Team America: World Police"