- Use a wired headset with a built-in microphone instead.
- Use the terminal keyboard layout, then use keyboard shortcuts.
- Update your phone software.
- There is no audio hardware kill switch.
- That is not normal, provide a description of which Wi-Fi/Bluetooth modem you are using.
Contact Purism support to replace your back cover, or you can consider 3D printing the part yourself using this STEP file: