Are all those changes still recommended for only running one or even maybe up too three 1080 TI's? Everything i find online is for basically 6 or more GPU's on that motherboard. I just want to make sure i set it up correctly when it comes time.
It's not absolutely necessary when you only run one GPU, but it's still considered a good practice to disable devices that you're not planning to use. So if it's a dedicated mining rig, then you might just get yourself familiar with the BIOS and disable all the unused stuff like audio, serial etc.
O lastly... Does anyone know if their is a big difference (Performance wise) in the following two GPU's for mining? (Bonus Question

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EVGA GeForce GTX 1080 Ti iCX GAMING, 11G-P4-6591-KR, 11GB GDDR5X (Core Clock-1480MHz / Boost Clock-1582MHz)
EVGA GeForce GTX 1080 Ti SC2 GAMING, 11G-P4-6593-KR, 11GB GDDR5X (Core Clock-1556MHz / Boost Clock-1670MHz)
Performance wise you won't see much if any difference between these two. The 1st one will probably run at a bit higher core clock by default, but you can always adjust the clocks manually.
Ya its going to be a dedicated mining rig that i will expand on as time passes, just gonna start off mining Nicehash till i learn more about the other mining programs and pools that are out their.