I would say that its not so much the head, but perhaps the shoulders are a bit too thick and meaty. You can make the neck thinner or longer to help make the head more distinct from the body.
Since the breast are not covered, it may help to have the breast point more to the side, as if rolling off the chest. But I don't think this is the solution, i think it is more of an issue that the breasts are too perfect. It is kind of this reason I avoid D and DD size breasts, either going smaller or silly larger. experimenting with different base bodies before experimenting with breasts morphs is usually what I do, but it usually helps to have something in mind first, but as I said it looks like you went for perfect boob so it looks more fake as a result.
I could see what you mean about the lighting around the edge on the transparent side, but it may be something you want to help make it easy to see the character.