After a wash with Eucalan, it seems that the sheeplot problem has diminished (click the thumbnail for the full size picture). It might still be a teensy bit noticeable, but not enough to mandate an immediate dyeing. Besides, I sewed in the zipper, which matches the natural colour of the wool better than it would a vanilla-scented tea-dyed wool.
However, the strange little flecks of red and blue still remain.
And check out that rowing-out. I think either the size of the piece I’m knitting, or the weight of the yarn, determines whether the rowing out will be obvious/be present: I’ve found that it’s pretty much non-existent when I knit with yarns finer than aran weight, and in swatches; it’s most obvious around 4.5 sts/inch or when I’m knitting something garment sized (this is a cardigan, with the entire body knit in one piece). This is all combined knitting, which allegedly minimizes rowing out. Maybe I should try the western style to see what happens.