[attractive nausea]

^ There is nothing wrong with lip syncing a few songs, if she wasn't lip syncing to rest her voice it would be even worse.

But i agree with you that her voice if def one of the most important thing to enjoy the show. I think someone saw her for the very first time during CDL 15-16 but unfortunately couldn't enjoy the show because of horrible vocals and was really upset about it. That's like one of my biggest fears so i hope she manages to not shout too much during the upcoming tour.
You could see a difference during CDL 14-15 and AT2015, she wasn't screaming anymore like she used to, not so sure about TA tour, i heard a few songs of the recording and she was struggling with UNITE! And well during CDL 15-16 it was a disaster.