Protest The Hero is one of my favs (well, only their latest album, not a fan of the first). I think they are a good example of a band that is technical but isnt overdoing it. As for their genre, In my opinion they would be more of a neo-classical for the most part, with a blues touch to some of their riffs. And even some thrash/speed/power metal elements here and there. Although the intro to Spoils is very progressive. Thats awesome you have the tab book, I probably should get that. So far Im pretty close to playing along with Palms Read, Limb From Limb, and Wretch. Some riffs though I have to turn down the tempo:p
Im surprised I never heard of Augury, they are ones I can probably get into, thanks :)
As for the Sleater-Kinney, sounds very Indie-rock-esque; Pinback (a fav), Modest Mouse (another fav), etc. Maybe youll like this:
Margot & The Nuclear So & So's (outrageous name!)
http://www.youtube.com/watch?v=pPoaox5JYqI
Ever heard The Project Hate? Fun to listen to. Its not technical necessarily, I would call them Industrial/Symphonic Death Metal I guess. The vocalist has one of the best guttural vocals when it comes to death metal:
http://www.youtube.com/watch?v=zNtTFyKM7xw&feature=related
I cant stand most folk/viking metal, but this band is simply just awesome, especially live. My friends joke around and call it "Broadway Metal", because it sounds like it would be the theme music for some Epic Adventure Broadway play, Robin Hood or something lol.
Turisas:
http://www.youtube.com/watch?v=u-tyhelg6KU
For the most part, Opeth is still my personal all around fav. Been listening to them and loving every second of every listen since 2002. Especially the Still Life album.