We don't even know why the hell she screamed.
If the mind meld was "two way," then Valeris could have seen in Spock's mind the exspected repercussions of Valeris's actions. The opportunity of peace gone, a resumption of hostilities, life's lost, life's destroyed, seen through Spock's eyes.
Valeris screamed because she fully realize just what she's done.
I get that he was trying to stop a war. However, the only thing he didn't get from her was the location of the peace conference. Again, he gets that from Sulu.
But, that he wasn't going to get that location is something that is known only in hindsight. Until Spock went "digging" through Valeris mind, he didn't know that the location wasn't in her mental possession. Until the mind meld he had every reason to think (or hope) that Valeris was a upper level conspirator with the full plan residing in her head. it was only after, that Spock learned that her knowledge was limited.
"You know, there are some words I've known since I was a schoolboy: ' With the first link, the chain is forged. The first speech censured, the first thought forbidden, the first freedom denied, chains us all irrevocably.' Those words were uttered by Judge Aaron Satiee as wisdom and warning. The first time any man's freedom is trodden on we're all damaged. I fear that today..."
If that first man's freedom that's trodden upon is a criminal, we're not all damages, we're all saved, we're all secured, we're all protected, every one of us. This meaningless recital is Picard at his addle-minded worst.
Excuse my language, but what bullshit.
Granted, we never know if there were any repercussions to his actions after these events.
Repercussions like the personal gratitude of the leaders of both the Federation and the Empire? Maybe a big shiny medal?
Why exactly would any of the heros care in the least about Valeris?
because she was a Starfleet officer who was a protege of their friend Mr. Spock, and she'd served as a respected colleague with them on a mission? Also, she wasn't evil, she was acting in what she thought was the best interests of Starfleet. She was just misguided.
Protege of Spock. Spock very easily could have accompanied Kirk and McCoy to the Klingon ship, this didn't stop Valeris in her actions. And regardless of the uniform she was wearing,
no she wasn't in any way "serving" with the people aboard the Enterprise.
