Kiara Calli, and IRyS Bae for sure, I kinda forgot what the other ones are. SNOT was the most obviously pre-recorded (besides the stilted line-reading and 3 of them most likely not being in Japan right now, pay attention to the camera; it often goes into 'AR-mode' where it can move around the girls in 3d, the live shots never do that).
Edit: And as for the delayed crowd reaction reactions; 1. Ping. 2. They have to act like it's crazy no matter what, they can't just say, 'Oh you guys are pretty quiet and don't sound excited."