Beachtek DXA-SLR PURE Camera Adapter (2x Passive XLR)

Will this work with canon vixia hf g40 camcorder?

Could I use the headphone output from my digital keyboard as input to this device to video record keyboard performances without the background noise ?

Would this be good for doing interviews with an xlr mic direct to it as well as the sound from a mixing board? would it take away the hiss?

does it need batteries? if so what kind?