Finished - with a couple of hours to spare!
Thanks for all the helpful hints here. After practicing my stranded knitting techniques on some mittens and following your suggestions to knit the stranded sections inside-out my puckering problem was no more. I was also reassured to see I wasn't the only one scratching my head over row 23 or wondering how to do the Kitchener stitch on stitches that had been bound off.
I'm happy with the sweater, but puzzled by why my yoke looks like it has buttonholes where I did the sssk's in row 24. I'm considering it a personal design element, but want to know the cause so I don't do it again. Any ideas?
Thanks, MDK, for this KAL. I've enjoyed being part of this Bang-Out and I've learned a lot, but I think I'll go back to Stopovers for serial knitting.