This seems to me to be more of a statement explaining why you want there to be a God than an actual argument for God. I say this because your premises seem to be more about what you think is right (or what you'd want) rather than what you can actually demonstrate. You have proven neither of your premises in this argument (regarding God and the universe).
Yeah, I've gotta admit I agree with this. The desire that there be "justice" in the world (or in the afterlife) says absolutely nothing about whether such justice actually exists. If anything it really only raises the question "who's justice?" Which God's justice? the desire for justice could be purely subjective. After all, many Christians over the centuries have felt totally justified persecuting Jews for being "Christ killers", and felt that they were doing God's work. In their eyes they'd be shocked to find out that God in fact didn't want them to torture, main, rape, expel and round up Jews. Yet when we today look back on these events we say, "there must be a God, because those poor Jews need justice!" But God, as seen by many Christians during the inquisition isn't even remotely the same way in which we see God today. So who's justice? The persecuted medieval Jew, or the justice of the persecutor who was doing the work of Christ?
Before anyone says something like, "yeah those Latins were horrible, but that's not us!"...think again. Orthodox Christians have done similar things to Jews and fellow Eastern Christians, not to mention Pagans etc. The desire for justice proves absolutely nothing other than that we really wish there was justice, we don't see it in this world, so we posit that it must exist somewhere in the next world.
Not to even mention the old saying about "if God was just we'd all
be doomed for hell"....or something like that. I believe it was St. Isaac the Syrian who coined that phrase was it not?
The OP raises a very interesting and intelligent question, one worth exploring and discussing and mulling over. Yet to me, it doesn't answer anything. It only raises questions; questions that have been asked since the beginning of our species probably.