What is a channel audit?
A channel audit reviews the public setup and the recent publishing record together: positioning, branding, cadence, formats, title-thumbnail pairs, visible engagement, and the videos that sit above or below the channel's own baseline.
The honest version also says what it cannot see. Impressions, click-through rate, retention, traffic sources, and subscriber conversion live in YouTube Studio, so a public audit should name the metric that would confirm each hypothesis instead of inventing it.