Arduino Pro Mini Power (simple question i think)

I have an FTDI break out board and a pro mini, as well as an RF transmitter connected together.

The RF transmitter has power and ground wires. The pro mini has ground and raw wires. Those are soldered together and are powered with 12 volts.

the FTDI break out board provides 5v of power to the arduino through the VCC pin. If I connect both power sources, (the FTDI breakout board, and the 12 volt transformer) will anything bad happen?

I want to be able to use my rx while using the serial monitor for debugging.

here it says raw OR vcc ... so that is why I am unsure

I think there are some possible issues with feeding 5V power back through the USB cable. For extra safety you can rig a cable for the FTDI adapter that connects everything except VCC. Alternatively you could put a switch in the RAW connection so you can turn that off when you have the FTDI cable connected.