I'm considering switching to linux but I'm not a computer savvy person, so I wanted to have the option to switch back to windows if unforeseen complications (I only have 1 pc). Is it just a download on usb and install? And what ways can I get the product key or "cleaner" debloated versions.
There's no need for a Windows key because your system is already registered with Microsoft. It creates a unique ID from your computer's peripherals.
So just pop in the USB key, boot from the usb key and follow the instructions. To boot from the USB key you might need to go configure the boot order in your BIOS.
This is the best answer I've seen in this whole thread. You're right that the key is not needed. Microsoft identified your system components and did the original activation based on the hardware you've got on your computer. All you need to do to bring back a licensed copy of Windows is to reinstall it.