Your post is full of errors.

I have read the Quran (not an easy task).  It does not "demand that its followers lie, cheat, steal, maim and kill all infidels."  It enjoins God's followers (not Muhammed's--he is merely God's messenger) to observe a high level of personal morality.  Islam was born in a tribal society in which conflict was a given.  Hence God prescribes various rules regarding conflict.  They aren't all consistent (the work as a whole is full of confusing passages); some require tolerance and even protection of "infidels," some encourage war against them.

"Sharia law" is not found in the Koran.  The concept of a reasoned legal system based on the Quran and the Hadith arose only after Muhammed's time.

Islam is unquestionably a religion "as religions are generally understood to be." At least, all comparative religion scholars so regard it.  Every religion, including Christianity and Buddhism, has sanctioned violence and unethical conduct toward (perceived) opponents.