GoForSmoke:
I think I'd put a resistor between pin 0 and GND. Pin 0 connects to the USB chip, you'd be grounding that pin too.
While that would be reasonable advice for an Arduino using a microcontroller without native USB, on the boards that do keyboard emulation the primary microcontroller itself is the USB chip. Pins 0 and 1 are not used for Serial. They are actually Serial1.