If im understanding this correctly, if you get this DSHidMini driver then DS4Windows will recognize the ps3 controller and you can then emulate a DS4 or X360 (but windows wont see it as an X360 controller allowing you to connect them all).
Maybe?
Yes it's a Win10 problem, no i don't think there's a solution. However if you use Retroarch i think it uses the VID/PID of the controller so there isn't an issue. You can also set this in Mame https://docs.mamedev.org/advanced/devicemap.html , i don't know about other emulators.
Same, I think i've worked out whats happening, in this case my sg1000 has a mix of images such as these, when LB chooses the smaller image it doesnt blur, my creativision are all the smaller images and none of them blur.