I would also suggest oh_my_zsh which adds a lot of extra functionality to zsh. The ‘z’ plugin is nice - easily cd between frequently used folders.

Just to clarify - you’re only using the Sense HAT for the joystick button to trigger speech capture and the LED display. Can it be made to work without the Sense HAT, maybe pressing a key on a keyboard to wait for input instead?

This means they’re too of the bigger space hogs on the Pi.