This is all very compelling and I'd agree your theory is more likely.
But I also think that it is easier to be controlled and calculated when things are going your way; it is not incompatible with letting your emotions cloud your judgement when things come crashing down - while still being smart and calculated over all.
The reason I stick to my current theory that it is probably a mix is because of something you said: the BH audience doesn't believe her. And for her to think she'd fool us when it is SO obvious it would be a much taller order than the current performances she gives, when she doesn't provide any fact or counter-narrative, tells ME that part of her behavior is indeed narcissistic delusion she can still pull it off because she is the victim and, surely, the audience will see it. She doesn't need to engage with the facts in her mind because that's not the point. The point is HER suffering.
She is a smart woman: if she were thinking about this rationally, she'd know she needs a better PR plan than this transparently phony fact-less BS.
Think about that Tom and the car story. That's not someone who is in control of her narrative and knows what she is doing. That is someone who sees herself as the victim and is convinced people will see it this way - even if I don't doubt she is indeed giving a performance to get the audience there like she did to get the audience where she wanted in her previous "personality"
They had started to dip their toes into the waters around this point - I believe ABC actors started doing chats with Prodigy, AOL, etc. in 1994 and 1995 - but it definitely was not a thing for a majority of the audience.
I also had no idea it was Gwyn. Admittedly I did not see the full story (I think I started watching around the time Curtis died), and I didn't really know the history of the characters, but Christine Tudor did such a wonderful job playing the pain of Gwyn (the moment where we heard her cry out in agony at learning of Cabot and Isabelle still stays with me), and I was also completely fooled by the attempt on Gwyn and Ally's life. It still makes sense even after the reveal, because Gwyn was not one of those soap killers Henry Slesar wrote so well who had many detailed plans to survive - she would have been fine with dying that night (and she wasn't close enough to Ally to care if Ally died with her).
This was 1995. Online wasn't a thing.
I wonder if they could pull off a story like this now. Not just departures being leaked and stuff but fans putting together the kind of clues you mention.
I was genuinely shocked at some of the twists and turns at the time. And I had NO idea it was Gwyn until the very last moment.
I think any actor who is on a show for a decade and has been involved in at least two highly popular pairings can think that the show can give them something at contract renewal.
Any employee expects regular raises, regardless of what how their business does. What they do if they are not given that raise, or those non-financial parks, THAT is where we see if they have leverage.
AND a key to this is General Hospital was very publicly courting her for the high-profile recast of Carly. They had approached when TB left. It was an open secret (we fans knew). That certainly gave her a point of leverage with GL and she wasn't a complete fool to think she was in demand.
And in the end that's what happened. She may have stayed even after their "No dice" if she had no other option. But she had one big shiny one at her disposal and she took it.
I have less sympathy for huge stars like KZ complaining not getting raises. But I don't blame people who have a family to feed in the highly insecure world of show-business asking for improvements to their contracts once they have earned their oats.