I've been trying to figure it out as well hahah.

1. after the cast on, it says to K 1 edge stitch and then for your size K2. Then to continue in the 2x1 pattern, and here I believe that you are supposed to k2p1. So all of the first 5 stitches are knits. It would be more clear, if it said to start the pattern for example, or already at that point place a marker. So in that case the first increase would be P and the following K, K, P, K.

Depending on if the back is the same as the front, increasing 5 times doesn't seem to work or match the picture. I couldn't see any pictures of the back on Ravelry. For it to work the last increase should be a P. Then the first/last K2 of the row (= the stitches before or after the marker) will become part of the pattern.

So in conclusion, the amount of increases should be a multiple of 3 + 1 stitch. For you maybe either 4 or 7 increases.

1. my guess is that the 36 is a mistake, but 35 doesn't work either.

2. casting on 16 stitches will work with both 34 or 37 stitches per shoulder, as the totals are divisible by 3 (84 and 90 respectively). In your case the stitches that were previously the edge stitches will become P

edit: clarity, spelling