No. External power is not supported. The USB 3.0 ExpressCard prefers its internal 5V power to external 5V power and will not use an external 5V power source.
No. NEVER PLUG A 12V POWER SOURCE INTO A USB 3 EXPRESSCARD. USB is a 5V standard and it is not designed to take 12V. Applying a 12V source may damage the card, will void the warranty and may damage any connected USB peripherals.