I'm not familiar with the Windows platform but although you can have userspace USB drivers on linux, you still need to be able to run code that can talk to the sysfs interface.

Not really, as long as the firmware developers used OS 2.0 descriptors

(For the rare occurences that our customer is using 7 or earlier, we tell them to use zadig and be done with it.)

The Linux problem is more

Hope every time you want to interface with a USB device.