Corsi can prove his abiotic oil very easily - go out, make predictions about finding oil specifically where conventional theory said no oil should exist and make money doing it. If he can do that, repeatedly, people will start to take notice.

For now, Corsi is no more credible than whackos who believe in astrology. He is responsible for proving his crazy theories, not the rest of the world.

Of course we as rational people think that it's up to him to prove hsi theories, not up to us to disprove them. However, is this really how the "rest of the world" will view it? I think that most of them will--if they don't hear a resounding chorus of contrary fact from the exploratory community--either give credence to Corsi and his ilk because it's what they want to believe or--even more likely--simply shrug their shoulders and chalk it up to another scientific dispute that has no bearing on their private lives. That's the issue I am trying to broach. I don't care one whit what Corsi cares; he's only one man. I care how many people he manages to drag down with him because THEIR collective belief/inaction may have a profound effect on me.
If peak hits as we expect, and Corsi keeps up his nonsense, ultimately people will insist he put his money where his mouth is or he'll look more and more ridiculous.
I don't disagree with your assessment of how the "rest of the world" will view this dialog. That's precisely why I lean in the direction of collapse as outcome of all this. Corsi has connections, as evidenced by his participation in the Swift Boat affair. And Corsi and his ilk will block any dialog that threatens the US dollar hegemony, which is predicated on oil, even as oil starts to become scarcer. You can fight this fight with no certainty of winning or you can prepare in some other manner.
The experiment has already been done.  Prior to WW2 the origins of oil were not well understood; prospecting for oil often required a divining rod and a lot of faith that God was on your side.  If you started with the premise of abiotic oil you went out of business pretty fast.  Noting the geology of where drilling was successful lead to biotic theories of oil creation, not the other way around.

Perhaps the Corsian response would be that the abiotic oil is so deep that until recently we didn't have the capability of finding it, which would also burden abiotic proponents with explaining why these deep abiotic deposits don't migrate closer to the surface over billions of years.

The truth is that I wouldn't be surprised if abiotic processes generate trace amounts of hydrocarbons.  But I favor occasionally poking at the obvious holes in the Corsians argument but ultimately letting them come to us - if abiotic oil will save us from the peak, where is it?  Just find one 100 million barrel field in basalt with no sedimentary source rock beneath it and we'll let him sit with the grown-ups.  No Mr. Corsi, deepwater Brazil doesn't qualify.