Now that is scary. I'd like to read that comment, do you have an idea where and when that was made? I refuse to see the scene in that light. Hermione wasn't aware at that time that the centaurs
Hermione is ruthless. Absoutely. She fights to win. So does everyone else. I wonder what you think she could have done? She at least got them out of there. However, in her own words, she brought Umbridge there in the hopes that the centaures helped them, would drive her off. And Hermione was scared and surprised by the centaur's viciousness. However, she didn't show compassion for Umbridge, and frankly, neither did I. Just a moment earlier, Umbridge used Harry as a human shield against arrows. I can't have compassion for that. So maybe you're more compassionate than I - and Hermione. ;)
Her response was to quote The Art of War, and he cautions her about inspiring personal vendettas, whereupon she responds with general stubborness and nasties.
No, he snarls at her and spouts one of his Gryffindor slights. And she retaliates. That's what they do, and will do in future. You'll never see her become a doormat and find everything Severus hurls at her right and good, and what she deserves. It's the pot calling the kettle black. It's part of the fun in that pairing. They both have a certain amount of ruthlessness, nastiness and wit. They both have a rather similar kind of humour, more compassion than is obvious and are painfully loyal. They are perfect for each other. ;)
The agonizing:
You see - I don't see him like that. I see him trying to make amends, but not agonizing. I'm not a fan of 'I've been so bad, please step on me'-Snape. I like to see him move on, try to put to rights what he did wrong and not wallow about it all the time. He might even learn a lesson, hopefully, but as Hermione, he's a rather slow learner where his own faults are concerned.
*Who* worked with Hermione in canon? No one did. What she saw from people who should know better, are lies, manipulations, threats and violence. *Who* would have guided her? Certainly you don't mean McGonagall, that stupid old cow who never sees what's right in front of her nose.
The betrayal:
He betrayed the prophecy he just heard to Voldemort. He knew that people were affected and put into mortal danger. He didn't care. That's pretty bad in my book. Why he was allowed to do so is another matter. Dumbledore would have known. He did nothing. That's pretty bad, too.