Link Aren't all desktops going to have integrated graphics?
With an Intel CPU and compatible motherboard, the integrated graphics chip is built into the CPU. And integrated graphics is too slow for gaming anyway.
Good news is just by using a PCIe video card, you completely 100% bypass the integrated graphics.
Link Once you start a game, does the dedicated graphics card take over so even if integrated is dithering there wouldn't be any dithering in game?
As long as your monitor is hooked up to the dedicated graphics card, it is on 100% of the time.
if you wanted to disable the integrated graphics card, that can be easily done in the BIOS.
Link Would you be able to outline a ultimate dithering free gaming
I can give some sugesstions
Motherboard: as long as it's compatible in general with other parts, pick what you need.
GPU: Nvidia GTX 600/700 series GPU.
Monitor: native 8-bit monitor without dithering connected to DVI or DisplayPort.
Link Does any other hardware come into play for dithering?
Other than possibly the screen in the case of being 6+2 bits., nope.
Link Does windows version matter?
I do not know
Link Will any gpu drivers be safe on nvidia 6xx or 7xx?
I do not know with regards to dithering. What I can tell you is for a long time with GTX 500/600 series cards and WIndows 7 there was an issue where the computer would completely freeze up even the power button wouldn't turn it off, the last driver before crashing was 314.22 and it got fixed around the 337 series I think.