You only really need controller remap if you're hot-swapping usb devices 'on-the-fly.' If you have them plugged into the same usb ports all the time, then it shouldn't be an issue. For example, I have two usb ports on the front of my cab, to which I plug in any combo of gamepads, lightguns or guitar controllers. Not sure about multi-mouse - never used that setting in MAME. Maybe one only enables multi-mouse when there's-a multi-villains on the loose? I believe one projects cheese into the sky.