So Von, I went back and looked at a couple of your past WIWs to confirm my suspicion. I think you are right about the first outfit. Not that it is a fail! If you were walking down the street, I wouldn't think, wow! disaster! I don't know that I'd particularly notice it at all. I just don't think that this is showcasing all the loveliness that is you, which seems to be what you gut is telling you.
I think it is the weight of the sweater and the half tuck. And it could be the shoes. I could see you wearing the sweater (untucked) with the pencil skirt and the dark tall boots that you were wearing in an earlier WIW. You'd have heavier boots with heavier sweater and it would all look very outdoor autumn lovely. I even think that adding the extra weight with the footwear would balance the necklace. I bet you would really like the combo.
For a more feminine take, I'd go with the finer gauge on the sweater you mentioned. If it is a little slouchy or oversized, but drapey from being a finer gauge, I think it will give you the femininity you want, but knocked back from bombshell into relaxed and feminine territory.
Love the cobalt option and can't wait to see that as a stand alone WIW!