Why would a woman seek to "push her boundaries" in a sexual situation?

New things are fun. It's like moving on to rollercoasters once you can handle the ferris wheel or the tilt-a-whirl. Novelty isn't inherently bad.

Why would she use porn terminology like "gangbang" when referring to having sex with multiple male partners instead of a foursome?

Because a "gangbang" specifically involves the "bangee" as the submissive partner with the "bangers" as the dominant partners.

Does it benefit her as a woman as part of a class of women to pretend like her sexuality is not influenced by her experiences and the world around her?

Does it matter? Is exploring those feelings inherently wrong?

Can we gain any insight into the way she may view herself and her relationship with her sex when her fantasies include being "shoved to the ground"?

Can you? Do you have access to this woman's internal monolog? Or are you making assumptions about her behavior based on what you THINK she is consiously or unconsiously feeling and experiences she may or may not have had?

Recognizing social influences, norms, expectations, and class-based power structures (especially relating to male dominance and the patriarchy) is essential in radical feminism.

Oh, you can absolutely "recognize" social influences. But what, specifically, makes this woman's sexual experience "wrong" or "bad"?