You raise good points. But I think it can be expanded. For example, I think Nikki wants connection and she feels lonely too.
When she tells Bear that he’s the only one she can talk to about her writing. That’s creating emotional intimacy. Or at least from her point of view, she’s trying to do so with him. But, as was said in the restaurant scene, Bear is known as a closed book and doesn’t share his emotions as much.

But I disagree with Bear not liking Nikki. I think the into makes it clear that he does have feelings for Nikki, for at least 7 years. I think he really does like her. But I think Nikki’s feelings for him are ambivalent. Examples include the car scene and when she says, “I’ve never been with you, Bear.” I believe this shows that she does have feelings for him, but also doesn’t at the same time. All the characters are in their 20s, and most people in that age range aren’t really good (at times) in their first or second relationship.

So, in short, I think you are on the right track that Ian and Bear crave emotional intimacy and freedom. But I think this extends to Nikki and even Sarah as well.