Yeah the torture thing tugs at me too. Whenever I stumble across a torture chamber (Falmer, Thalmor) I'm always like "O SH*T" as there's like bloodstains across every surface, bones and body parts everywhere, and bloody rags and embalming tools. Makes me wanna kill 'em even more. Ugh.
Interesting that you should mention seekers. I'm actually rather fond of them. To me they are a bit like pugs: so incredibly ugly that it's kind of endearing.
As for the creature I hate, there are few things in life that I want more than to completely eradicate Hagravens from the face of Nirn. The first time I played pieces of the past, I had no idea that Drascua was a hag. Screamed. Died. It was a fun time.