to view a really nice project (at Raverly) that was knit with Blick Fang. She used a US10/6.0mm needle, and 1 hank of the yarn. I've read that the little knots in the yarn take some getting used to, but the larger the needle, the easier it is to pull the little bump through the stitch.
You are right about the yarn. It isn't going to allow fancy knit stitches to show off, so I'd recommend a stocking stitch, or a garter stitch. I'd prefer the garter stitch because the scarf won't roll into a tube when you are wearing it.
I really like the color of your Blick Fang!
At Ravelry, I typed the yarn (Blick Fang) into the yarn search bar. Then when I got to the yarn, I clicked Projects for the yarn. Then when I got to the Projects, I typed "scarf" into its search bar. That's how I found several projects that used Blick Fang for a scarf and could read what those knitters had to say about it, and see what needle sizes they successfully used.
Keep us posted on your progress! I'm dying to see how your beautiful red colorway works out!