Some additional info on the USB and WiFi Issues:
It seems to be caused the interference issue between the USB 3 standard, which can emit noise in the 2.4 - 2.5 GHz spectrum, and the 2.4 GHz WLAN band. I'm seeing the same problems with my Surface Pro 4, when I am connected to a 2.4 GHz network and have data transferred from my external HDD. To me it is a shame that these problems even exist in in these "premium" products, and I need to say I'm very angry about that. Of course, connecting to a 5 GHz WiFi network solves the issue, but you don't always have the possibility for that. In my case, due to business reasons, I am living in a hotel for the next 7 month, and I am not able to use my external HDD and the internet a t the same time!
More info the the interference issue can be found here:
http://uk.pcmag.com/networking-reviews-ratings-comparisons/13179/opinion/wireless-witch-the-truth-about-usb-30-and-wi-fi-interference