some of your "contradictions" are just not there
the one, for example, about creation, gets the numbers and content wrong in surah 41.
about alexander the great, he is never mentioned by name in the qur'an. "dhul karnain" is mentioned, who some people assume is alexander the great. if what you say is true, then it's probably not him.
about the inhericance numbers, you applied them wrong. there are many conditions stated in the qur'an which adjust inheritance. you adjusted them, or whoever gave you the idea adjusted them in an incorrect manner
about the angel of death thing, you're ignoring the rest of the qur'an. "nothing happens, unless allah wills it" so, it may be said that God is causing me to write, just as he caused you to write, while at the same time i wrote and you wrote. it's a matter of theology, and hardly a contradiction. God takes the soul at death by having the angel of death take it, if he so wishes. God may do things in whatever manner he sees fit.
basically, errors arise when people who don't know theology or the arabic language