If extreeeme weight saving is needed (e.g. for drones), many of the ports and jacks can successfully be removed, as long the corresponding functionality is never again needed for your application (there’s no going back with most of these surface-mount parts):
- GPIO header
- HDMI port
- Composite video/audio port
- FPC display connector
- Camera connector
- Micro USB power connector (if regulated +5V is instead fed to the appropriate pins on the GPIO header).
Most of these parts are about the same height, so there’s little point in removing a subset as a space-saving measure. But for aerial applications, every gram counts…go nuts.
If all of the display options are removed, then the system can only be administered remotely (e.g. ssh through WiFi). If all of the USB ports have also been removed, then the only way to log directly into the system is with a serial console cable connected to the appropriate pins on the GPIO header.
Sometimes it’s easiest just to have a second, unmodified Raspberry Pi for administration tasks. Move the microSD card to this system, boot and perform whatever configuration is necessary, then shut down and move the card back to the pared-down board.