A:AnswerIf you are so inclined, you could code a solution as well that allows you to control these and more functions without having to go through the proprietary "Armory Crate" long story short if the hardware is there you can do it. (Pro tip: if you are trying to find a solution more than likely someone has already coded it.)
A:AnswerIf you're going with the qhd display then you will want the 2070 to make the most of it. Aside from that you will get better cooling from the 15, I personally like the 14 form factor.