- The vessels of wrath are "preparing themselves" for destruction (v. 22)
- Hate does not mean hate (v. 4)
- Paul is talking about nations, not salvation of individuals
The vessels of destruction, which refer to the non-elect, are indeed prepared in advance for destruction. Anything else is tap dancing around unconditional election. Still, they are equipped with a free will which, corrupted by original sin, has caused them to make sinful choices from the time of conception. Hence they are also preparing themselves for destruction.
Moderate Calvinists are also sensitive about this issue, wary of the dreaded double predestination charge. They want God to be active in election, but passive otherwise. Scripture teaches that God is not passive with the non-elect, simply leaving them to prepare themselves for destruction—which they do quite skillfully—as, but for the grace of God, would we all. God does more. He hardens Pharaoh's heart. He gives sinful men over to their own desires (Rom 1:24). This suggests activity on God's part, not to make a man evil, he already is, and not in making a man "more evil", and not merely to pass over, but it suggests actively removing restraint. Upon removal of God's restraint, man actually sinks from a state of total depravity, a condition wherein he has no moral ability to choose God but may still act benevolently (with ultimately sinful motives), toward utter depravity, where there is not even a pretense of goodness.
Scripture could not be clearer on the issue. While one may argue weakly that God is not the subject in regards to the vessels of wrath (v. 22) there can be no doubt about Pharaoh, presented not as an exception but rather an archetype: "I raised you up for this very purpose, that I might display my power in you and that my name might be proclaimed in all the earth," (Rom 9:17). It does not say God waited around until Pharaoh adequately prepared himself. Pharaoh was created as part of God's sovereign plan, he was not a "savable" man who, in spite of prevenient grace (which, if it existed, was evidently insufficient and therefore useless) made the wrong choice.
As for hate not meaning hate, that is something of a red herring. One could hardly argue against the obvious: God showed favor to Jacob that He withheld from Esau. Call it what you want, the two did not have a equal playing field.
Part of the problem here is that, with good intentions--but forgetful of our status as creatures, we want to apologize for any apparent aspersions on God's character that the bible seems to teach. God cannot hate—God is love. God cannot create vessels for destruction—God gives all the same shot. But we are required to believe what is written about God, not what we would like to have been written. Paul says as much in his preemptive strike in v20-21.
Romans 9 is most certainly about individual salvation. Any other exegesis is, in my opinion, tortured. Of course it starts out as a heartfelt lamentation for his (Paul's) countrymen (v1-5), but Paul segues in an interesting manner. First in verse 6:
It is not as though God's word had failed. For not all who are descended from Israel are Israel. (Rom 9:6)
Here Paul says that the charge that God has not kept his promise to the Jews is unfounded, because not all who are descended from Israel are Israel. This is the beginning of the transition to individual salvation saying, in effect, Israel as a nation is irrelevant—it appears superficially that promises have not been kept to the Jewish nation, but they have been kept with the new Israel.
Paul emphasizes this in verse 8:
In other words, it is not the natural children who are God's children, but it is the children of the promise who are regarded as Abraham's offspring. (Rom 9:8)
Couldn’t be clearer. Tracing your DNA back to Abraham ain’t worth a bucket of warm spit. It is the children of promise who are God’s children. Who are they? That's up to God, not bloodlines.
The children of promise are of the entire world. For the rest of the discussion related to election, Paul has set aside any notion of nations or races. He is telling us that God has chosen, individuals as Abraham's descendants (v 8), that individuals are given mercy at His discretion (v 15), and that these individuals were chosen ahead of time (v 23), and that their choice has nothing to do with their will (v 16).
Later, especially in chapter 10, he assures his country men that they have not been totally cast aside, that Jews, like men of all other nations, will be among the elect.
By the way, when discussing the question "Does God Love Everybody" I wish I had thrown these two verses into the mix:
The arrogant cannot stand in your presence; you hate all who do wrong. (Ps 5:5)
The LORD examines the righteous, but the wicked and those who love violence his soul hates. (Ps 11:5)