Hi there Michael,
U can use it, it is 1.5V. P9z68-v Pro uses a different CPU. U have P8Z68.
Yes it is compatible, even if it is not on QVL list. It just means that the RAM was not certified(Corsair didn't pay for the cert. process).
It was also released after the mobo was. And nobody has all the RAM certified, as they make too many to list them all
i7, i5 socket 1155 is @ 1333MHz and 1.5v requirement.
It will run on your RAM , but if u will not OC @ past 4.5GHz, it is not really needed.