(1) If God created us, then He cannot gain anything from us, since whatever we have to offer was given to us by Him in the first place. Therefore, God creating us is pointless.

If God has perfect knowledge of the future, his creating us would be pointless as the only thing he can gain from us is the knowledge of our actions, and perfect knowledge of the future would let him know the complete outcome of any system he plans to start, making it pointless for him to ever actually "create" anything.

If God doesn't have perfect knowledge, then he actually has to create us to learn of our actions, which is the only thing we can offer him.

(2) Does justice come before God or does God come before justice? In other words, did God create good or did God take up what is good?

If you believe that everything God does is just by definition, then God comes before justice.

If you believe that there are things God wouldn't do because they are they go against his nature, then justice comes before God.

(1) If God created us, then He cannot gain anything from us, since whatever we have to offer was given to us by Him in the first place. Therefore, God creating us is pointless.

So if I make a gun I cannot get anything from that gun since I gave it all of it's properties? No, I get non physical things from the gun, such as but not limited to, protection, security etc. Though if this were true, that would mean humanity is not responsible for it's own sins, because God made them already.

(2) Does justice come before God or does God come before justice? In other words, did God create good or did God take up what is good?

Good is subjective. It doesn't really exist, what I call good is probably different than what middle easterners call good, so basically it doesn't really exist. That said, God took up what is good because what he saw as good he made the law of being good.

I'm interested in reading your essay on the topic. Care to share it with us?