^ To be honest, I don't think that's a very good idea. Keiko or Hikaru don't seem to be showing any signs of health issues, so mentioning their performances might sound more like outright criticism. Similarly, asking a bunch of questions about things like the choreography might also give off a critical impression.
(Plus, I'm not sure if Kala deserves to be singled out for live criticism anyway. There's no way of knowing if FJ performed somewhat badly at times back in the Vol. 2 and 4 DVDs, since we have only one unedited performance from them. They might be equally shaky, and we just don't know it.)
Wakana's showing signs of struggling, and that's a worrisome thing. I think we should address that first and foremost, and then ask about the other things later, if we do get an answer about Wakana.