human have weakness , and religion is the best we can do ( human mind and greediness has also entered most of the text and made it corrupt , but that is a different issue)

you will find most of the answer to questions you raise above in this one

https://medium.com/p/5718c20ad0c1

I don't agree to your problem of empathy "Empathy is harder to have when you don't directly see the suffering your actions are causing", lets take an example of alcohol, drugs ; cannot most of people empathize with people and families who has suffered because of it and make rules to ban them but no, because it go against liberalism and individuality ?

true religion is the only thing that can balance relationship between people, families, societies and nature else I dont see any amount of rationality can produce a Just system ( but you can try); also you can see the evidence now in term of world wars and fascist leaders all of them were non religious...

As I stated earlier , we are still in same conversation which we were may be 3000 years back at time of Socrates; and have killed millions in process with no solution and more disunited and more unequal then we ever were ( only thing we can agree on is yes we made lot of technological progress and able to develop lot of cure for disease etc - but one funny thing is that now people are saying we have are too may now for the planet to hold)