A. Sending phantom power to a dynamic mic, or one that doesn’t require power, will not affect the microphone adversely. This may not be true on older ribbon type mics, or microphones that have their own power supply. One should check with the manufacturer to make sure.

As for the high impedance input, phantom power travels along the third, or ground wire of the 3 conductor XLR jack. Therefore, it is not part of the high impedance signal at all.