Measuring against the Gold Standard

I'm trusting that measuring my first sock against a SmartWool sock is the way to go to determine length of the leg and foot. And if Charlene Schurch doesn't keep records of rows worked, but just holds the first sock up against the second to measure for a match, I can do that too (I thought that I heard her say this on a KnitPicks podcast, and if it was wishful thinking, I'm going with it.) Though sock number 2 is far in the distance.

The Louet Topaz is much more comforting to work with than the fine weight. Still size 3 needles, but somehow, I seem to be knitting more tightly on what must be my 11th or 12th effort at this sock for my husband. The color is advertised as Pewter; in person, it's more of a soft brownish grey, but fine for a man's sock.
And no pictures to show, but I'm almost done with the Budding Lace section of my Swallowtail shawl. Does this qualify me for a Knitting with Nora button?

Right now, I'm either going for a walk and getting out into the springy air, or sitting down to (re)work the heel turn on my sock. This yarn's a bit splitty, and I think that I hit a reworked portion just as I was (re)working the heel area. Experienced sock knitters: should I be using reinforcing nylon thread along with the wool for the heel area? And if so, what type do you like, and where do you find it?