reset() and dump()

dump() tries to work out what the pins were set to by looking at the state of the hardware. My guess is that D12-14 are used for something like the serial port, but the Espruino compile for the ESP8266 that you're using isn't aware of that.

For @Kolban and @tve it's to do with the IS_PIN_USED_INTERNALLY macro created by build_platform_config