You justify premise 2 by claiming that it is possible that God created everything except humans. — Raymond Rider
Slightly more than that - I claim that it is entirely possible that God created nothing. Being omnipotent, omniscient and omnibenevolent does not, so far as I can see, essentially involve having created anything at all.
God knew that humans would eventually come about, but He certainly did not want them. God merely permitted humans to come about but was not involved in their creation. — Raymond Rider
I would not make that claim. God would have stopped us coming into being, for he would not want a person to come into being without prior consent.
The combination of theism and antinatalism thus gets me to the conclusion that we have not been created, but exist in the same manner as God - that is, we exist with aseity.
God exists and billions of other souls exist. And nothing has created any of them, for some things exist uncreated and we and God are among those things.
These souls - some of them - are evilly disposed. We know this, for we are those souls.
To be evilly disposed is to be disposed to behave in ways that God disapproves of.
What would God do with such souls? Destroy them? Seems too harsh. Quarantine them? Yes, surely. That is what we ourselves do to those among us who show themselves to be very evil. We have the power, as a society, to destroy them. But we do not - we imprison them. And we imprison them primarily to protect innocent others from them; secondarily to give them something of what they deserve; and finally to reform them.
Thus as the best among us imprison the worst, it is reasonable to suppose God would do the same. And as we are not living in a world that God would suffer innocent people to live in, we can safely conclude that God is doing it to us: that we are in prison. And if we wonder what we might have done to deserve to be here, exposed to all the risks of harm this world creates for us, we need only look to those who, knowing what kind of a place this is, think nothing of exposing innocent others to it by breeding. Those who freely and knowingly suffer innocents to live in ignorance in a world like this one deserve themselves to live in ignorance in a world like this one. And here we are.
Evil is a deprivation of goodness, much like cold is a deprivation of heat and does not actually exist. — Raymond Rider
This seems false on its face. There is goodness, badness and indifference. Absence of goodness is mere indifference, not positive badness. Take cruelty - what is that an absence of? Kindness? But someone who is indifferent lacks kindness. To be cruel is far more than merely 'not' to be kind. And so on.
So the privation account is implausible and also does nothing in itself to overcome the problem of evil as it just relabels evil 'absence of good' but leaves the question of why God would permit it unanswered.
If God gives me a glass half empty, then there is a problem of evil: why did God give me a glass half empty when he had the power to give me a full glass, and the goodness to want to, other things being equal?
It does nothing to solve this to insist that the glass is not half empty, but half full.
God has not created us. He would not, as antinatalism is true. And nothing save religious dogma commits the theist to thinking he created us.
Why would God create creatures like us? It makes no sense. There is no benefit that accrues to us through being ignorant and evilly disposed. And God would not create us anyway, as to do that would be to make a significant imposition on another without prior consent, which is not something a good person does to another unless necessary to spare them some greater evil (which does not apply in the creation case, for the uncreated are at no risk of anything).