Regarding the POE, if there is no camera using the power, nothing is done with it, like a outlet without an appliance connected to it.
The Camera can be powered with a POE injector; you can place it direct near to the camera and run a cable to your switch.
Hi I'm using the Thinkware F770 with a front and rear Full HD camera.
Satisfied with the recording quality, but struggeling to stitch my files together to get a larger video.
It's the drivers for the audio that I need to sort, but that is something PC related and not for here ;-)