1. Divine test is not for Allah to know us. But rather for us to know our limit and the unlimited potentials given to us by Allah. Test is to make us perfect and to appreciate the free will given to us by Allah.
The test neither harm not benefit Allah. It’s rather for our benefit if we truly ponder and reflect
2. Indeed God is omnipotent and omniscient. God is is the one who taught us the importance of circumcision. This shows that he want us to be part of shaping our creation and destiny. He could have created without man and man but makes sure man and woman have saying in it. It shows nothing but Allah’s respect for His creations