Er - you have read Andrew's first sentence?
Yes, but there were loads of things before then - as Marco says above
As Rowan Sjet said that has nothing to do with the fact that you were ignoring one crucial sentence from Andrew's post when answering. Basically you were only refering to FS, when he specifically was asking about horrendous things we knew about before FS.
The problem I had with Dukat in FS was that it just doesn't fit his character in my opinion and that has nothing to do with "sympathy". I'll just quote from
my review:
I think that while the "Illiana-as-Kira held captive by Dukat as his sex doll" plot adds quite a bit to her character, on the other hand it’s taking away too much from the character of Dukat, in my opinion. Sure, he is a megalomaniac, sick, cold-hearted bastard who has conceivably raped many women, but I don’t think he is the kind of man who would have fun raping a drugged woman. As I see it, for him the "fun" lies in the act of breaking people, but you can’t do that when your victim isn’t fully aware of her surroundings. But even if you don’t take the drugging into account, before she got her fighting spirit back he had basically broken her already during the time of her captivity, to the point where she doesn’t really care anymore. I think by this point at the latest, he would have lost interest, no matter how fixated he might be on Kira. So having him act like that kind of ruined one of the few truly interesting villains of Star Trek a bit for me.
Based on what I've read here, I don't think I am going to be looking for this book. I know that, in general, you shouldn't judge a book you haven't read, but in this case I am sure that the plot about Dukat raping and torturing Iliana Ghemor is... how shall I put it?
Ah yes... UTTER CRAP.
It is completely out of character for Dukat as we've gotten to know him on the show. And not because I think he is a 'too nice' to do that. He is not. But because that's simply not him. For two reasons, which all boil down to one: essentially, Dukat is a narcissist, obsessed with making people love and admire him, obsessed with being the hero. He wants women to want him and love him and see him as their hero and protector - even while he's abusing his power and manipulating them into 'voluntarily choosing' that which he has already decided for them. I don't believe he would literally rape anyone, simply because there is nothing there for him, that is not what he is after. I liked "Wrongs Darker than Death or Night", because, to me, that was completely in character for Dukat - he abuses his power over Bajoran women and uses their vulnerable position to play his 'I am a nice guy, saving the poor Bajoran woman'. And through this, just like with everything he does, he has to be able to convince himself that he genuinely loves them and is 'helping' them. Before his "Waltz" insanity, Dukat never even admited to himself his deep-seated anger and hatred for Bajorans. There was never any indication that he was even consciously aware of it, let alone 'releasing' these feelings by torturing and raping a drugged and imprisoned woman. This seems like nothing but a bad, unconvincing retcon.
First of all, what pleasure would someone like Dukat get from this? He could try to break her spirit so she would accept his help and 'love' and be grateful, that I can buy. But he's gaining nothing this way. Remember, for him, the victory consists in making one's enemies realize that they were wrong to oppose you in the first place.
And second, how would he have been able to justify such deeds to himself? Even if she was really Bajoran - as I said, he was still convincing himself that he was 'helping' the Bajorans. But a Cardassian woman - how would be possibly be able to justify this to himself and see himself as a magnanimous hero?
I. AM. NOT. BUYING. IT.
It seems that the entire Pah-wraiths thing (which was stupid in itself, but still kind of could have worked as far as his characterization goes, I guess) is not enough, and that some writers' idea of writing Dukat is "let's see how eeeeeevil we can make Dukat".

So Dukat is a bad guy - that means he'd do literally anything evil we can possibly think of, right? Because that's what bad guys do? WRONG. People do things that they are inclined and motivated to do. Characters in fiction should do things based on their characterization - not do bad
things that don't make sense just because
you have decided you want the audience, or in this case, the readers, to hate them.
There is a good reason why novels are not canon. With all due respect to some wonderful authors out there, including those who visit this forum, Star Trek novels are, essentially, glorified fanfiction. Some of them are excellent - but then, I've also read some excellent fanfics. Unless I am mistaken (and please correct me if I am wrong), novel writers, just like fanfic writers, are free to come up with just about anything, without having to consult a bunch of other writers, showrunners, producers...and convince them that it would work, make sense, be a good story. You also don't have to worry that you'll encounter any opposition from the actors (who often take their characters more seriously and care about the integrity of their characters more than the writers do) - in literature, character assassinations are so much easier, since there is no resistance.
As for those people who argue that this plot makes Dukat/Kira/Kira's mother plots more disturbing.. oh please, is this even necessary?! Wasn't Dukat/Meru relationship - and Dukat/Nerys - already disturbing enough? And IMO, even more so because Dukat was not a one-dimensional monster and Meru was hard to classify as either a simple victim or collaborator? In a way, I thought what Dukat did to women like Meru and their families was more disturbing on some level than it would have been if he was simply raping them or openly treating them as sex slaves as we've seen his subordinates do, because an emotional manipulation that we've seen goes so much deeper, morally and emotionally, compromising them and creating a gap between them and their families and their people in the way that would not have happened if they were simply rape victims without any responsability for what happened to them. If Meru had hated being Dukat's mistress, Kira might have seen her as someone who was sacrificing herself for her family, and probably would not have come to hate her mother and consider her a collaborator. I'd always rather have moral ambiguity and emotional complexity over black-and-white 'evil monster tortures helpless victim' stories. The latter, IMO, is just playing it safe, and making it simpler and more comfortable for people who don't like to think much.