One thing I never understood, when Frank asked Julia to bring him Larry she steadfastly refused. However in the movie all we see is her showing coldness and disgust towards him. At that point in the movie she made a transition of the reluctant lover to sorta finding a knack for finding a killing the men she brought back and starting to like doing it. But she refused to had over Larry despite admitting she did not love him. When frank taunts Julia while Larry is kissing her she freaks out crying saying she can't bear it, so if she hated him and planned on leaving him, why did she protect him initially?
Larry was just a dorky guy, very safe, middle of the road... this is why Julia grows cold towards him. Frank was the "bad boy" type and better lover, so having had that, she just doesn't feel for square Larry anymore. But she loved him once, otherwise why would they have got together to begin with. You can grow distant from someone and at the same time not want a demon from hell to consume their soul.
The guys from the bar, she purposely got people she had zero emotional investment in. There is no way she would have had zero emotional investment in Larry, she wanted to leave him, not kill him.
In the movie Julia grows progressively more and more evil. At first she is afraid to commit murder and looks like she's going to be sick after she does it. But she starts to get used to it and even enjoy it because it makes her feel sexy, desirable and powerful. Even then she is unwilling to sacrifice Larry until she has no choice. She doesn't love him but she likes him and doesn't want to hurt him before then.
In the book. Julia didn't love or care about Larry. She was only with Larry because Larry had money.
But Julia was able to convince Larry that she loved him. But in reality. She only loved his money. And Julia was hoping that after marring Larry. She would still have Frank as her lover. But he disappeared after the wedding. And we all know what happened to him.
Actually it was said that she did care for him at point but after experiencing frank she saw Rory as boring and a poor lover at which point she stayed for financial stability.