I didn't think it was out of character for Mio, really. I just think she got caught up with whatever it was with Mika's concert, and kinda took off with it. I mean, heck, first thing she does is become a backup dancer for some really big idol, then she gets a CD. She's always seemed to be the type to take a wave of energy and kinda take off with it, and it seems more to me she was riding off that first concert in full-on cowabunga mode. So yeah, reality check is gonna be harsh.
Producer... well, he tanked his Charisma stat, so yeah, he kinda messed up when he tried talking sense into her, but I'm glad he at least tried - dude's got a spine, and he's not afraid to lay it to 'em. Did she overreact? Maybe, but hey. People blurt all sorts of stuff out when they're feeling like the walls're closing in, whether or not it makes logical sense in the grand scheme of things. Mio being impulsive ain't that odd, I always figured her the type. So when the Producer showed her how much of a lady killer he ain't... what'd he say again? "Of course this would've happened?" Well, her mind thought it, and it went straight to her mouth. I don't think that's unlike her.
I kinda like what's happening though, because what's the first thing you learn in storytelling? Conflict. Gotta be there, or you get pointless plots or Gary Stu gutter trash. I dunno about anyone else, but seeing the bad side of a character makes them more complete as a character. But meh... maybe I misunderstood her character from the start? Don't think I did, but eh.
... Though I have to admit, I'm getting a little tired of Daisuki. Especially the ads.