Hi! This sweater dress looks absolutely stunning! As regards the "holes" that you said were created in the neckline: I am assuming that they were created because of the sorta "shortrow" technique used in the bind-off that you mentioned.
When you have done any knitting the says "knit X, turn, knit X...turn, knit X...etc"...that can be shortrow technique. If it is, maybe look and see if you are picking up the little "tag" on the return trip (when you turn and go back). This will prevent (and close up) the hole.
Amy has some 'short row' videos here at KH. Even if her videos don't exactly pertain to your pattern directions, you will see the technique of picking up that little tag so as to prevent the hole.
Here is one link:
Hope this helps you perfect the neckline of your sweater dress! I think it deserves to be all that you want it to be! You have worked so hard to make this dress 'just right'. I admire that!