Torah, errors, MTT and DSS

I was fundamentally believing Torah to be without errors re. its commandments for the last 11 years - first as a devout Christian for six years. 2007 I started doing my best to keep the commandments of the Books of Moses and rejected Christianity. For a while (and until recently) I had beliefs very similar to the Karaites.
Later on I have started to study more information that scrutinizes what I did believe.

Some of what I have learned recently:
The whole concept that the non-dimensional Creator, who is non-physical, would require/need any physical sacrifice is a concept that some Israelites borrowed from pagan polytheistic religions.
The Creator has NOT commanded us/given us the right to kill any sapient beings, including animals, which He created. The Creator wants us to take care of and love all of His sapients being.

Why would anyone ever assume (as many religious texts do) that the Creator created life and wants man to kill what He has created?

Mikey wrote: "How has it been changed? "
The research on which these Yale University-lectures are based on, is evidence of many errors, contradictions and late redactions of the Torah:
http://oyc.yale.edu/religious-studies/rlst-145/

That MT and DSS are similar doesn't prove anything. The redactions of the Torah took place before this.
The Bible-text itself contains many contradictions.