1) Assuming that God is all powerful, all knowing, infinite and love and there is not anything that he feels is missing in His existence, what was His reason to create human beings?
2) The end of the world for every single person will occur when he dies. Why should there be a collective end of the world when the individual end of the world is guaranteed?
Thank you for your interesting questions.
1. We do not know why he created us, we just know that He did and He loves us. You could ask the same question about the angels...what is their purpose? Don't know...you would have to ask Him.
2. I am going to assume that by "collective end of the world" you mean the final judgement. Our fate is sealed once we parish. Before death each person chooses what side they are on...Gods or Satan's. Everyone will be resurrected again for the sake of understanding the eternal judgement (either in the first or the second resurrection). The questions of, "Who is able to go to Heaven and who is not and why"? Will be answered. It is at this time that we are able to look into the works of God. His judgement and mercy will be laid open for us (all human kind) in order for us to be able to understand why some people are called righteous and why some are not. He wants us to understand His mercy and His justice, yet not only us, but other worlds and their populations as well (not to mention the angels).
Hope that makes sense?