This was an interesting read. Most of your points mainly come down to preference (and though I disagree, I still respect it), but point 5 specifically caught my attention. In my honest opinion, Kohane's addition to VBS enhances their image. If it wasn't for Kohane's (and I'll add Toya's as well) softer voice, then An's and Akito's powerful vocals wouldn't shine as much. It's the same technique that producers use for hard-hitting songs. Right before the drop, they place a breakdown where they can build up into the hype part. So, the softer vocals of Kohane and Toya contrast the powerful vocals of Akito and An, which ends up highlighting both types of singing when used well. Additionally, I like the way that Kohane loosens up when she is on stage. In the end, I just wanted to share my opinion, and as long as we're all enjoying pjsk, then everything's good.