Eh, the "siege" didn't bother me that much, understood that the scope was limited for technical reasons. But yeah they could have done better via other means. I guess they could have had you scurrying about Vergen to different areas to save the line - heh, like Seltkirk. When you're running around with Roche it does seem a lot more frantic and chaotic though. For the mist, I know Geralt says it will spread, but I don't think he ever said it would do so "soon", seemed like he was talking in a longer term than the plot time covered.