What most people ignore is that these rules were meant only to be applied by Jews to other Jews. So "Thou shalt not kill." becomes "Thou shalt not kill another Jew." Gentiles were fair game. You could kill them, steal from them, sleep with their wives, tell lies about them and covet everything they had.

As regards the First Commandment, we must bear in mind that there was a regular Divine MOBA going on back in the day. Dagon, Ishtar, Amun-Ra, Ba'al, Zeus and all the rest going at it hammer and tongs. The Hebrew I AM was the unifying principle of the tribes, as the other gods were of their respective nations, and as such was the only one ot be worshipped.

As to graven images, they're heavy bastards to lug around. Not practical for nomads.