For the case, the anodizing will isolate each panel from one another. Many people use a bit of sandpaper or abrasive to clear the anodizing in a small area in between panels, and where the PE ground is connected from the IEC terminal.
As for the PSU ground, I would not connect it to the chassis directly, but use a ground loop breaker (see https://www.diyaudio.com/community/threads/audio-component-grounding-and-interconnection.163575/).
For the case, once you are satisfied, I would check with an ohmmeter to make sure you have continuity.