An optical drive is not needed to install Windows. That can be done with a usb stick.
For a non-overclocking build an NH-D15 is not optimal. The Hyper 212 EVO will do a great job.
An H170 motherboard saves a bit without affecting performance.
I would go with an ssd. Save the M.2 slot for a 4-lane PCIe 3.0 drive. The OP M.2 unit is not really any faster than the 3.5" ssd model. An M.2 (M) ssd OTH is significantly faster. Also more expensive. The Samsung 950 PRO 256GB M.2-2280 for example is more than US$180.
While Sapphire suggests a 750W psu, it is not necessary for this build. Something around 650W is more than enough.