SU is not about talking rather than fighting, but addressing problems no matter where they lie. In this case, all of Steven's "new" powers are really just powers he's never accessed because he's never gotten really, really fucking pissed. All of the powers he usually uses are tied to positive or otherwise not-bad emotions, stuff like his affection for his friends, self-esteem, protective instincts, that kind of thing. The powers he's starting to manifest come from other places: doubt, frustration, anger, etc. I don't mean petty anger like when you're just annoyed at something, like how, say Kevin is annoying to Steven, but real anger, like the kind of anger you feel at some ongoing life travesty, or when a shitty month extends into shitty years, or when a relative of yours does something stupid you know you can never ever stop.
Steven is developing, or rather just starting to exhibit, powers based on the deeper negative spectrum of his emotions, places he's touched on sometimes but never really plunged. SUF is about Steven confronting his personal issues as opposed to other people's. If he doesn't confront and address those problems, his negative emotions, they will destroy him and everything he loves, make him like his mother, etc. I don't know why people are surprised that one of the most powerful Gem types can do all kinds of different bad things, and I for one am looking forward to possibly seeing Steven wrecking some shit.