Well... I made a swatch for the entrelac turtleneck this afternoon, and proved to my satisfaction that I can get the required gauge without having to change needle sizes from what the pattern specifies, and that entrelac really will suit the hand-painted yarn perfectly and accomplish all my various goals for this project. I used a single skein for the swatch, of course, so the sample does not show what the mixture of colors & tones will eventually look like, but at least you can see that the yarn and the pattern seem to like each other.
I have also wound all the skeins now, and determined that I can group them by color into four categories. There is one especially pale creamy one, three alike that have the creamy background with blue & green leaning more toward pastel, two alike that are mainly light blue as opposed to cream, and three alike that seem to emphasize the darker shades of blue and green. So I will base my color scheme on those ratios (1, 3, 3, 2).
What a difference a day or two can make!! When this week started, I still had a great big pile of lovely yarn and only vague, incohate ideas about what to do with it. Now I have the ideal pattern, a definite game-plan, and every reason to expect that I will start seeing results sooner rather than later. Woohoo!!