"You shall not covet your neighbour's house, you shall not covet your neighbour's wife, or his manservant, or maidservant, his ox or his donkey.
"Remember the sabbath day and keep it holy. Six days you shall labour and do all your work. But the seventh is the sabbath of the lord your god; you shall not do any work - you, your son or daughter, your male or female slave, your livestock...."
You're bound to notice the references to slaves and livestock in both of those. Moreover, commandement ten lumps the wife in with the rest of the chattel, suggesting they were part of the property, and proving that this wasn't written for women to read.
What can be gathered from this? they are addressed to a nomadic people whose main economy is primitive agriculture and whose wealth is sometimes counted in people as well as animals.
Thou shall not kill, certainly not the easiest example to reform. But do note that mere human systems have done better in distinguishing different moral scales of homocide. And certainly with this moral scale's enforcement in the last century, crime and homocide is infinitely less common than it was when the commandements were first written.
I have no authority in the church's laws, nor do i need devine authority for the laws i follow. However the Catholic church's dogma claiming papal infalibility would mean that he has the power to ammend such things.