I understand that it is not too difficult to learn Japanese and Korean simultaneously, as they have similar grammar and share similar nouns. However, I can only imagine that speaking Mandarin is quite challenging. I am truly impressed by NiziU, especially Mako, and the amount of effort she put into learning it.
The audio is being recorded over a cell phone so you shouldn't expect it to be what you hear at the live performance. So go a little easier on the audio people and equipment.
Then you should move on. Your bus is late so step aside for those of us taking the NiziU express to Tokyo and the world. By the way the flip side of being an idol is dealing with anti-fans. This is normal for those who are successful. I am a fan and consider myself a WithU member. You are an anti-fan group I call Not-WithU.. So go away and find another tree to bark at.