I doubt I will have any issues. On new hardware? The issues you speak of would have shown up on 7 by now. Thank you for your concern, but I'm sure it's OK.
It bodes well to realize that even two of the same machines will interact differently with an os or programs.. hand built machines typically more so..
It is not unheard of that an older Os will run better than a newer one..sometimes just the hardware configuration or the hardware it's self can be a determining factor..
Is it typical to buy parts with issues or simply ones that don't work at all?? Actually yes.. I have over the years of building machines come across many many instances of broken or sub-par performing parts, right out of the box..
Had a brand new ram stick that messed all kinds of stuff up, "Mind you that it took some time to catch on that there were problems" they were nether obvious nor instant... It held its own during benchmark tests, but after yanking it out of the machine, the problems stopped.
Brand new OEM screen for my sons laptop I replaced recently, wouldn't work with the Dimming/brightness software installed by the MFG..
So yes a piece of hardware that "works" can still be not "working properly"...
Also.. I cant remember who said they didn't like all the windows8 *start menu Apps* hogging up bandwidth or resources. See here for instructions on how to uninstall them.. uninstall windows8 apps