Okay, so I rolled a Bleak Walker, maxed out stealth on my two level-ups (upon leaving Cilant Lis and after having the dream in Gilded Vale) and headed straight for Raedric's Keep. Kolsc approached me in Esternwood and the three dialogue choices I had to end the conversation were: "I can handle any threat on my own."; "Why don't you come with me?"; and "Thank you for the warning. Perhaps I'll return later." Regardless of what I chose, the journal entry remained the same, mentioning that Raedric was a tyrant that people wanted removed from the throne. I then went to the keep, broke into the sewers, stealthed my way to Osrya, tried both killing her for her key and completing her quest to get her key (without killing any guards), and my conversation with Raedric was the same: he mentions how Kolsc hired mercenaries to do his bidding, and there's a Bleak Walker-specific response of "Save your words, for they do not move me. I will end this feud here and now."
There's a small chance that the conversation with Kolsc might go differently if he approaches you in Gilded Vale after completing a few quests. I'll try that tomorrow to see if it changes anything, but I'm pretty sure it doesn't because that's what I did in my previous Bleak Walker playthrough. Regardless, I'll give it one last shot tomorrow.