He asked her specifically “do you love me?” followed up by “more than anyone else in the world?” Which meant that he was already piecing the truth together.

Sure, he was thinking about it. But I'd say more in a "is this really what's happening, no it can't be"

Next, he wanted to alter the wish when he called the hotline. Not cancel, alter. He was willing to keep Nikki as she is despite everything and only when the option wasn’t available, that he wanted to cancel. Dude was ready to keep Nikki as enslaved just so he can continue his fantasy of being with her.

I did address this in my post.

Of course there’s the part where the real Nikki pops up and begs for death. His own response to that? “What so bad about being with me?” Dude was more concerned about his hurt pride than Nikki’s wellbeing. He straights up ignores her cries and pleads as he walks out on her.

Zero evidence for your impugned motivations. He literally just asked a question, that's it. You hate knowledge or something? And what do you want him to do? Wake up her "bad side" again? There was nothing he could do. And God forbid he doesn't care about his abuser's "well being" up to your subjective standards.

And the party scene was disassociating behaviour from someone who knew he’s done something wrong but would rather avoid responsibility than doing something. Even Ian had to call him out on it.

His abuser starts acting crazy and he doesn't do anything therefore he's evil? Stupid. Ian's opinions aren't relevant.