Note to new readers: when Auggy says “LFW” he means “Libertarian Free Will”. (He mentions it without the abbreviation later in his post, but I wanted to make sure visitors and new members understood for sure what he was talking about. 
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I think critics who complain that God would thus be the author of sin, have a good complaint to make. Even if God acts to confirm a sinner in their sinfulness (hardening their heart after the fact)–which is what a lot of those Biblical examples seem to involve (though not necessarily all!)–and even if this ‘mere’ confirmation is only temporary (which is also what a lot of those Biblical examples seem to involve)… {inhale} 
…it’s still true that God has authoritatively acted to ensure that at least some injustice is done that otherwise might not have been done. The archetypal example is the Mosaic Pharoah; several times he’s willing to let Israel go, and God hardens his heart to be stubborn, resulting in more injustice to Israel. (Other times however Pharoah seems to choose of himself to be stubborn.)
The people (usually Arminianistic) who complain about the (usually Calvinistic) concept that God authoritatively chooses who will and who won’t do evil or good, and then acts or chooses not to act (which is itself a choice) to ensure this happens, don’t always perceive that if God hardens people’s hearts to confirm their choices even only temporarily (and most Arms would say God eventually does this PERMANENTLY to at least some sinners) then IT’S STILL EXACTLY THE SAME PROBLEM IN PRINCIPLE THAT THEY WERE COMPLAINING ABOUT! The only escape would be to say that God never chooses to support evildoing at all. But that’s going to run against some large swatches (some famous, some obscure) of scriptural testimony, OT and NT both.
It runs against the metaphysics of supernaturalistic theism, too.
If supernaturalistic theism is true (including trinitarian theism), our system of Nature, and the persons who are created inside it, do not exist in ontological independence from God. That would be the same as saying God has created a cosmological dualism; which is not supernaturalistic theism anymore (if it ever was). Moreover, equally ontological entities are unable to affect one another at all unless they exist dependently themselves within an overarching reality–so now we’re not even talking about cosmological dualism anymore, if God is supposed to be acting in Nature in any way! The concept that an Independent Fact could create another equal IF fails under scrutiny (if that other entity is created then it isn’t really an IF); but even if that was possible there would be no further relation possible between the IFs.
No, if supernaturalistic theism (including ortho-trin) is true, then we not only depend on God for the beginning of our existence, but we continue depending on the continual action of God for our properties and continuing existence, too.
Consequently, whatever else is true, the fact is (if supernat-theism is true) that God does act to support evildoers and so to support injustice, at least temporarily. That still remains true even if derivative free will is given to the persons for them to make ‘their own’ contributions to the story.
(I’ve been talking about this over in the BSM series for a while now, by the way. )
So there is no escape, whether one goes Arm or Calv in emphasis, from the conclusion that God as God acts in ways which in some senses directly support the unjust–even if God is intrinsically against injustice.
Consequently, if God hardens someone in their sin after the fact, that wouldn’t be out of character.
It wouldn’t even be out of character for God to manipulate someone into sinning on occasion!
But–and here’s the big BUT as far as our forum topic goes 
– if orthodox trinitarian theism is true, not only supernaturalistc theism, then God must be intrinsically dedicated to fulfilling mutually supportive interpersonal relationships for all people.
If there is injustice (and we all agree there is), then God as God must be the author of injustice to at least some degree, seeing as how all things (even rogue angels, or powers thrones and principalities if we want to think of such things impersonally) were created by Him and through Him and for Him, and it is by Him that all things continue holding together. God creates people, and doesn’t snuff them out of existence or revert them to good little puppets the moment they even consider doing evil. He at least allows them to continue to exist and even directly acts to keep them in existence.
But if ortho-trin is true, God must be aiming at bringing those persons back into good fellowship with all persons (whether created or uncreated, man or God).
The key problem then is whether God is finally the author of sin; whether God acts toward fulfilling non-fair-togetherness (un-righteousness) between persons. Which is what sinners, so far as we are sinners, do.
If universalism (this or that kind) is true, then the answer is no; whatever else God does, He does so acting toward fulfilling all fair-togetherness (righteousness). Even temporarily supporting evildoers, loving the sinner though hating the sin, can be done with an eye toward achieving that goal someday.
If universalism isn’t true, then the answer is yes: God acts ultimately toward fulfilling non-fair-togetherness between at least some persons; whether God annihilates some persons out of existence (preventing them from ever being in fair-togetherness with Himself and with other created persons), or abandons them eventually by giving up acting to save them from their sins, or never even intended to save them from their sins to begin with.
But then, neither could orthodox trinitarian theism be true.
