Looks like you got a lot of good information Spirit, so go ahead and digest it. :)
I've been reading it too and comparing to my own seat, and being the hardcore Dressage gal I am, I still prefer to align myself with classical principles which state "You should hardly work the horses mouth at all" infact the only mouth work I do is flexion, and that's usually after I have asked with my leg and seat both "nicely" (a squeeze and siting heavier) and "strongly" (giving them a kick and becoming more animated in my posting trot.) But I like to control the horse with my body, and use no "backwards motion." But that's the wonderful thing about Horse Forum, you're going to get a lot of great examples of how many different people ride their horses. But I agree with what an earlier poster said, that a lot of these principles will "click" easier once you're working with a trainer. :)
Sunny Black is...
Stallion owner, Assistant trainer/instructor, and Friesian Lover ~ <3