Er - you have read Book 2 of Fearful Symmetry?
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.