Classy Slip Up for a man (abandoned)

This is my first attempt to adjust a pattern (the Classy Slip-Up from Knit Socks) to fit a real person, in this case, my DH. It simply didn't work! I think the problem is that I second-guessed myself. Here were the measurements I took:
1) Width of foot (not circumference, which is probably a better number): 4" at the widest part
2) Length of foot (heel to toe): 11"
3) Length of heel flap (ankle bone to sole): 3 1/4"
4) Widest part of the foot (diagonal across the ankle):For 13 1/2"
5) Circumference of calf (taken about 4 in above ankle): 12"

I knit a small swatch and estimated a gauge of 4"=28 sts (on size 1 dpn). The pattern stitch requires a multiple of 4, so I calculated that 13.5" would require 94.5 sts. The Kint Socks! book siggested subtracting 10%, which left me with 85 sts, and rounding down to be a multiple of 4, gave me 84 sts to cast on.

I initially cast on 84 sts, and knitted about 1 inch of k1p1 ribbing for the cuff. At that point I asked DH to try it on, and it seemed really loose, by a couple of inches, so I unraveled, and co 68 sts instead. When I knitted 1in, and then 2in, I had him try it on, and it seemed to fit, so I continued with the sock pattern.

When I was ready to start the heel flap, I asked him to try it on again, and it seemed a little snug, but I optimistically continued. By this time he was getting annoyed with all the fittings, so I decided to just finish it, and accept that I might have to unravel it. As you can see in the picture, I didn't get all the way done, because I had a gut feeling that it just wasn't going to fit. So I asked him to try it on one more time, and he couldn't get the cuff over his heel! I have no idea what happened, because it seemed to fit before. There must be some influence by having a bunch a stitches compared to having just a few rows, that tightens the knitting.

So I took a couple of pictures, for posterity, and I will unravel it, and put off trying to make custom socks for him, until I have more experience.

Another issue is that this yarn, once kitted up in this pattern, just seemed too heavy. It's a Reynolds Kids Cottontail yarn, 60% cotton, 40% microfiber. 50g = 116 yards. According to the label, it knits up 20 sts and 28 rows with size 6 needles. According to the chart in Sensational Knitted Socks, this would make this yarn a DK weight.



I must have done something wrong, too, when picking up the gusset stitches. The "seam" curls under, instead of laying straight. Argh...

I think this yarn isn't suitable for socks. Maybe I'll make a bikini with it, or something small enough that only requires 150g (3 skeins) - a top-down halter top?