Buddha and Peace

When we talked about Buddha, two things come in mind: World peace and Do not know about God.

Buddha explored that we are suffering because of our own reason. Hence, we can solve it by changing ourselves. To materialize he suggests five things to take care. (1) Do not hurt anybody in anyways including all living being. (2) Do not smoke and do not pollute the body where your soul is rest. (3) Do not drink alcohol to maintain consciousness all of the time. (4) Do not cheat anyone, stand in yourself (5) Respect women. Can we imagine what happens if everyone follows these five rules? It is nothing but peace in real sense. If everyone becomes Buddhist, can we expect world peace? No, People have to follow these rules.

I was thinking why Buddha did not like to say anything about the god. Is there any chance that people will be away from Dharma while five rules in place? Do a teacher need to teach a primary student about what they need to do when they are in college or just need to teach them to be able to go to college successfully. I think Buddha did the same thing in the context. Buddha provided optimistic views.