what yuriman said, plus
you have two cd/dvd/blueray drives, you need zero, but if you really want to do the install via DVD, then get the bluray writer only.
i prefer W7 to W8.1 and W10.
you will not need a card reader either, unless you have an old camera.
you will not need a fan controller either, you can control them from the motherboard.
the 980ti should last you 3 years, so it's not a bad buy. if you want to wait for the next gen, sure, why not.
me, i'd rather go with a no-window Fractal Designs Define R5 instead of teh corsair, but they are both top class cases anyway.
i don't think you will need cable management over what you get with your case.
if you play FPS games (from your mousemat, it looks like it), you might want to consider a tenkeyless keyboard; they are smaller thus giving you more space to move the mouse, while keeping both arms straight.