Those are pretty much Yuu's interpretation of Touko's feeling, but she might be totally wrong, y'know. :p
I think this is what'll end up resolving the issue. The reason I love this manga so much is that Nakatani adapts the "unreliable narrator" into visual format so well. We see Touko as being terrifying because Yuu finds her terrifying in that moment, but we don't know any more than that.
For example, is she nervous about having to clarify why she's happy? Embarrassed about having said it, and therefore conscious of Touko's scrutiny? Worried about how Touko might interpret it? Does she think she's going to disappoint Touko's expectations and be abandoned? Is Touko even psycho at all, or is Yuu just perceiving her that way?
Same for how we don't see Yuu's actions framed as indicative of romantic interest (stuttering, being blinded by Touko's fabulousness, being okay with Touko kissing her). She doesn't know what all of that is, and, since the narrative is from her perspective, it's not framed that way.
Maybe I'm giving Nakatani too much credit. :p