As far as the Ellie poll is concerned, it must be 1,3 or 5. With 3, the (nude) pics of her, the most likely, since in the first teaser pic she has her phone in hands. If she stumbled over Logan with another girl, she hardly would want to be reachable.
Alternately, if it is for instance 5, she might contemplate doing something daring, to stay interesting for Logan, but is not sure if she should do it. But like another member said, we still need Logan and his friends.
We don't know but I doubt Ellie would unless pressured to
Not necessarily, we can influence how open/daring Ellie turns out to be during several events, there is a characteristic in game for this.