At first I wondered why Peter didn't just teleport the kid to heal Hiro, but then I thought it would probably make the kid feel used and could push him back over the edge again. To me, it was inconvenient, but not really a plot hole.
As for Emma, I like her, but the show feels totally different whenever she's in a scene. It slows down tenfold, and is like moving in baby steps as she struggles with her new found ability. It's something we haven't seen in quite some time, but it's kind of a throwback to season one, and I like it for that reason. But I can understand how it feels out of place considering the frantic, helter skelter pacing of the rest of the show.
slickkill, you've never heard a deaf person talk before? Haha, sorry, I find that interesting. Emma does seem to actually have a better grasp on enunciating than many deaf people do. But who knows. Maybe her ability helped with that (considering she can play instruments based on seeing the colors alone...talking could work the same way).