Can you link to the pattern?
"Shape Shoulder, here's where I get lost. Bind off 17 sts at beg of next row and foll alt row. Work 1 row. Bind of REM 18 sts. (There are NOT 18 rem. sts, there are 35) "
You're at 52 sts at when you get here, right?
Bind off 17 sts at beg of next row - you now have 52 - 17 = 35 sts
Work the next row, whatever your pattern is
Bind off 17 sts at beg... foll alt row. 35 - 17 = 18 sts
This is why I thought you missed the 2nd set of 17 sts to be bound off.
Happiness is catching that dropped stitch while it's still fixable..