Big E is very angry with Ioan and she’s grown up thinking it’s normal to demean and insult him. Alice instilled that in her and it seems she’s also irate that he didn’t choose her over Bianca - again like Alice.
The soda clip showed her behaving a lot like you’d expect Alice to go off (a tantrum), the emotional overreaction and yelling at him through pursed lips and all. It’s what she grew up with, her main role-model behaves the same.
Elsie seems a very different, in a different incident she was quietly filming the abuse playing out in front of her and then tried to change the subject to calm the room.
What they have in common is trying to navigate life with a drunken self absorbed mother. People talk about love bombing but Alice spews out all her bile the moment she feels rattled and we know how ugly that gets. That in itself might drive big E to want to live with Ioan but he would be getting an angry teen who learned her relationship behaviour from Alice and has no respect for him or his partner at all.
I believe Elsie is genuinely struggling with her environment, she seems very isolated and dependent on Alice for the little company she gets. She needs her dad and would probably benefit from a relationship with Bianca but is scared of the repercussions if she dares go there.
i think it’s understandable he is keen to move ahead quickly with Elsie’s custody but more cautious about Ella. Until she actually sees him as a father that deserves respect it would be very unwise to move forward with custody there. It would be chaos and everyone would suffer.