I'm not saying it's better. I've just said that type of USB won't make any difference when it comes to keyboard because it isn't storage device where you need high transfer rate. For peripherals USB-C is same thing as 5000+ DPI in mice - just a marketing trick.
USB-C wouldn't make any diference when it comes to keyboards and how Cherry switches could be worse than Razer switches which are made by Kailh or Gateron.
If it's installed correctly and BIOS can't see it then it's probably dead. You can also try to do update of motherboard BIOS without M.2 in it and see if that will change anything.
Logitech G403 HERO may be good for you, its size is something between Basilisk and G502 but it has same HERO sensor as G502, which is currently one of the best sensors on the market.
Remove battery from motherboard for about 10 minutes and then put it back and try to turn on your PC.
You'll need to set your BIOS settings again after you'll do this.
It seems there's no other way to install AiO in this case so I would flip this fan on the right side to be intake too so it will blow more cool air into case and it will also cool VRM radiator.
Move swap file to other drive.
You can also instll SSD Fresh and set it to automatic mode. It will turn off services that are bad for SSD. http://www.abelssoft.net/ssdfresh.exe