[jerf]

I can't help with the coil whine, but replacing the Wifi card is cheap and easy. I bought this on, albeit for the 9550: https://smile.amazon.com/gp/product/B0167N9R8E/ref=oh_aui_se... which is currently showing as $25.

Yeah, we can blame Dell a bit for this, but Wifi drivers are a problem for a lot of systems.

Replacing the fan may be worth a try, too. Google for the service manual for your system which will give you a step-by-step instruction guide with pictures, and the parts are easy to come by.

Still can't help with the coil whine or the trackpad, though. (Though generally I've heard people say it's the best trackpad outside of Apple. I can't speak to that, my standards for trackpads seem to be relatively low compared to a lot of people's, because I've been content with a lot of trackpads that the consensus says are bad.)