Can I connect my Macbook Pro to a Windows 10 PC via usb-c for more than just power?
Your PC is not a keyboard and mouse, so no, it cannot be used as a KVM.  

Just like your Mac, the keyboard and mouse on the PC are USB devices - it's just like a regular mouse and keyboard, just permanently plugged in.  They are "end devices" and your PC doesn't present itself as an HID device so there's no way for your Mac to see the PC as an input peripheral.