When the key battery is low you will see a warning in your display telling you to replace the battery. As for the headlights, maybe there is an issue with the light sensor.
For the instrument cluster and the clock etc. I recommend that you download Google translate and use it as a guide to set the options to your liking. You can take pictures of the Japanese text and highlight it using your finger to translate into English. This is how I set the clock and some other settings in my wife's Honda N-wgn. Play around with Google translate and see if you can figure out stuff.
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