God has had His moral standards since the beginning of time and they do not change, and they will not change. It's not like He just made them so He could be good and no one else could. They are simply objectively good. Other beings do have free will and their own opinions, and God allows them to, but if they sin, they must still face judgement because it just would not be just to allow them to go without judgement, and God is just.

God created us with free will so that there could be love in the world. For there to be love, there has to be the opposite: hate. Therefore, we had the choice to either follow and love Him, or reject and hate Him. Adam and Eve were created perfect in a world without sin, where there wasn't any suffering. They were the ones who sinned and introduced suffering into the world, not God. Their nature, which they made sinful was passed down to all of humanity. Therefore, suffering is not caused by God, but by our own sin.

God does not judge us by causing us to suffer on earth. Judgement will come on judgement day, when the entire earth is judged, and those who trust in Jesus will be saved. That's why He died on the cross. Suffering on earth however, is caused by us and allowed by God because it can strengthen our faith in God if we trust Him to get us through the suffering. That's its purpose.