You just have to wait. It's possibly that Lavi have something important to do in future, we don't know. And Hoshino always impress us, I least I back her up in it. She always impress me.
I laugh the hell out of me when Kanda enclosed the CROWS, that was a funny scene and how Jhonny was "The hell? I better stay quiet /sweat"
Aaaaand Kanda did say why he came back to the Order, but as a real exorcist, you just have to analyze what he said to Lenalee and Master Zhi (I really don't remember his name, it's difficult to me). Now, He's free, he can do whatever he likes and I think he really appreciate his Nakama, that's why his doing it (for me). Remember that Allen didn't quiet as an Exorcist, he just wanted to do something alone and for his Nakamas, to protect them... But know is a traitor in front of the Black Order's Eyes, like Jhonny (it seems that Kanda now is fugitive, I understood that through reading th chapter, maybe I'm wrong).
I think he wants to save Allen or a least kick his ass really hard for doing things alone.
I'm curious why Jhonny appear so much, maybe it's because he believed more in Allen than anyone else. My theory is that Jhonny is going to gain an innocence, but is possibly (as someone in this thread said) that he could be the heart, but how? Apocrypos should had felt the Heart, 'cuz the Heart is sad. I think Apocrypos knows where is the Heart, or a least he has clues. And maybe Allen is part of the Heart.
Whatever, my stupid theories. I want to see next chapter.