All of this AU Dukat experienced in a partially symbolic fashion.
Oralius kept AU Dukat from realizing exactly who he saw, because it would be too painful of a burden for him at this point in his life. (Remember, AU Dukat is only 20 years old...by AU Cardassian legal standards, he does not become a man in the eyes of the law until age 24.)
AU Dukat was not physically present in "our" universe, nor do I believe the canon Dukat was aware of the crossover in a fully conscious sense. I do think that subconsciously, he definitely
experienced the moment. The lashing-out that AU Dukat experienced as an attack on himself, subconsciously that was the canon Dukat attacking and attempting to kill the part of himself that is like this AU version.
I felt like the canon Dukat came back to the Kornaire incident for a reason, as his mind was breaking down again in "Waltz," that it had to be significant. The way he described it--that it haunted him for days on end--made me think that maybe, just MAYBE it was the very last time in his life when the other part of him might actually have been strong enough to try to break through to the surface. (A little something survives in him, until he takes the Pah-Wraiths into his spirit. But that part of him has been beaten within an inch of its life and can no longer make a meaningful difference.)
As for Oralius trying to work on all Dukats--yes. However, I carry from my own faith the principle that deity will not work on an unwilling heart. AU Dukat accepted Oralius' influence...the canon version did not. And I DO think there is the possibility of Oralius working on someone's heart even though for whatever reason they cannot acknowledge her by name. Tekeny Ghemor and Tayben Berat are examples of this...they ARE receptive even though their culture has conditioned them against actually recognizing what's going on as spiritual. (CS Lewis does something similar in The Last Battle
, with Emeth.)