God damn this manga is a mess. It really ended the volume there, didn't it? Well, time to sit back and watch the dominoes fall.
I do think I disagree with your reading of Mami, though, at least in part. It's not so much that she doesn't or didn't have romantic feelings for Touma (considering she's basically used him as her excuse to not go out with other guys), but that she's trying to find a way to be at peace in the "friend zone," even knowing her feelings won't be reciprocated. Touma outing himself to her with that old classic, "there's someone I like," is his attempt to make that implicit rejection easier for her. (This volume is especially hard to talk about in isolation, but the same idea is touched on again way later.)
But I can probably use testing both readings as an excuse to go back and reread, again. Certain parts of this manga are entirely too well-constructed for an author's first work in the genre.