You would have to strand the yarn, especially for the two stitch groups you mentioned. When you do, however, make double sure to leave your strands nice and loose or you'll end up like I did, with an unwearable sock!
I knitted up this cool looking argyle pattern only to find it wouldn't go over my heel.
I don't think you'll have to worry about hooking your toes on the strands, just be a little careful when you first slip the sock on and once your foot stretches it a little, the strands should tighten up so your toes won't catch them. If you have to float more than 4-5 stitches, then you'll need to twist the two different color yarns to "lock in" the strands, otherwise the first stitch you knit with the stranded color will go a little wonky.
As for the color changes six rows up, that you could snip the yarn and re-join six rows later if you wanted, but carrying up the six rows shouldn't cause a problem since socks need to stretch more horizontally than vertically. HTH