Nope. Didn't miss that, thanks. Although IIRC that happened prior to Torygg's taking power as High King, since it was about 25 years prior to 4E 201, and Torygg is implied to have been a very young king. He would have been a child, if that, during the Markarth incident. So different government, different playbook.
Not at all. Even if Torygg is not responsible for the incident itself, he's supporting and promoting the same policies that led to it.
I don't believe we know anything about the High King prior to him...it's possible he was a puppet king, or at least more in step with the Empire, and that's why Ulfric was tossed in prison.
Ulfric mentions Torygg's father. He says "Torygg was a puppet of the empire, not a true high king of Skyrim. His father, maybe, but not Torygg." Obviously he had some respect for him.
The whole point is not Torygg's culpability. Ulfric didn't hate him. Nevertheless, he had to go, one way or another. The duel forced both Torygg's and the empire's hand. Torygg could have saved his own life by declining the duel and letting a moot convene to decide his kingship. He wasn't willing to do that. So, too bad.
She says that now, after Torygg's murder, which adds to her bias and gives her a reason to speak rather ill of Ulfric. Did she, or anyone else for that matter, think that about Ulfric at the time of the actual moot? We don't know.
If none of them spoke up at the moot one way or another, it doesn't matter. Actions speak louder than words, and so does inaction. Ulfric spent up to 15 years in prison because the empire, and its representatives in Skyrim, are bent over and taking it from the Thalmor. He didn't come in guns blazing at first- he spoke out about independence at the moot. Torygg and his court remained silent. That was their answer.