Damage isn't just a matter of the rules, though. A living being is in tremendous pain when it gets its arm shot off or stabbed in the gut, a droid isn't. If you roleplay wounds even somewhat realistically, organics will be occasionally incapacitated by pain. Droids won't.
Actually, Wounds (points on the WT) don't really cause any pain in this system. That's a function of weapon properties and critical hits. Droids have no special resistance to either of those.
I wrote wounds, not Wounds. I also mentioned going beyond the rules and into roleplaying.
And yes, Wounds are physical damage. They most certainly come with pain, even if the system doesn't track the pain of wounds. Just like it doesn't track a whole bunch of combat details. Doesn't mean you get setbacks for having Wounds, but it does mean the GM can spend threats to give you pain-related setbacks, and that roleplaying someone who's been thoroughly shot or stabbed will look quite differently whether you're doing it with an organic or with a droid character.
Droids feel pain when their feet are burned. They have no special resistance to pain. Roleplay as you wish, but someone could equally say that their character is resistant/immune to pain if it's just a fluff bit as opposed to the rules.