As for lightsabers themselves, I've already decided they can't be used by non-Force-users. No on/off switches, just a mental command to the crystal. In fact, probably a big penalty if you haven't attuned it previously. So sorry, any smugglers wanting to cut open a giant space kangaroo are gonna have to use a knife
I see your argument, and raise you one instance of Han using Luke's lightsaber on Hoth. But you could always attribute that to latent Force sensitivity in Han, or else Luke subconsciously allowing it to be activated. Either works.
And General Grevious would be another exception?