What struck me most is that the filming team isn't used to filming live musical numbers, let alone live TV. The skills mismatch there was obvious. And behind the scenes, the control room was likewise unskilled. This was neither sports nor drama, but some weird hybrid of both. Making the whole thing look good was a challenge to them. (What they taught me was just how good early TV cameramen were, and especially, how good golden-age musical cameramen were.)
Suggestion by me: take your team and film lots of live musicals where possible. Your team needs to practice their basic live skills just like dancers need to dance every day and singers sing. The results will show.
As for the voices, I enjoyed them. Every woman singing has verve, but their stage presence wasn't equal. Of note was Dorothy. Being school age, most of her experience was on the stage, so she was playing to her strengths. She sounded good and she had good stage presence. The pure singers struggled with stage presence.
Mary J. Bilge showed her chops while singing, by God, but not while acting. She had to hold down the Wicked Witch number. I felt that the choreography here was weak, the dancing lifeless (more so than the choreographer intended), and Mary's part just too stiff. She had to pull off WICKED not merely in voice (which she did superbly) but in presence (which she didn't). Honestly, they really needed a triple threat here, and those sorts of actresses are thin on the ground. The Wicked Witch has to have instant stage presence, a great voice, and good dance moves.
I thought that Brand New Day wound up feeling too stiff for it's joyfulness. The reason, I think, is because the choir offstage couldn't adapt to the number as it flowed. They sang as they sang, unable to really interact with the show behind them.
I really liked "He's the Wizard." That showed what this show does really well. It didn't contain any of what the finale contained. The musical number was smaller, allowing for easier camera work. The dancers covered for the non-dancers very well. The non-dancers got to move about. Everybody in the number did well, even in closeup. Amber Riley had both voice and presence, but her comedic timing fell flat. However, once the music began, she lit up and sang, her backup singers were all on stage, and they all performed in and with each other. It worked as a unified piece. And the longer that number ran, the more energy that it contained. It didn't peter out, it caught on fire. That's how you know something is working.
I salute the choreographer. I may criticize, but given the challenge of singers-not-dancers who had to look not-dead in the musical numbers, the choreographer rose to that challenge admirably.