The throttle yes, but it's a bad idea, little gain and no advantage. In the mid-60's some Jap bikes had left footed brakes, right shifting,Everyone who borrowed or rode another type had trouble. You've been left handed all your life, you know how to assimilate, so assimilate.
It wouldn't be that big of a deal to swap the throttle to the left as well as the clutch if the base is separate from the light switch housing. But that will make the throttle work backwards, so you'd have to reverse the ends of the throttle cables at the carbs. And you'd lose the mirror mount on the clutch because it would then be pointing down instead of up. The brake is a totally different story. Swapping it to the left side would turn the reservoir upside down and it would suck air, causing it to not work. About the only way to do that would to be to find a master cylinder from something like an old Kawasaki Z1R. That bike had a remote brake master cylinder with a cable operated brake lever. If you're talking about moving the rear brake pedal to the left, old Brit bikes had a left side brake. In the mid-70s the used linkage to reverse the brake and gear shift. So yes it could be done, but would be complex and expensive. Why do you want to go to all the hassle you describe? I'm right handed (not sure about which foot) and I and millions of other bike riders (right and left handed) have no problem operating the clutch lever, gear shift, direction light switch and high beam switch with our left hand and foot. And on cars the left hand and foot is pretty busy as well. In short, if you physically and mentally can't adapt, then you better stick with riding a bicycle and leave any motorized vehicles alone.
No, you cannot switch the housings that contain the brake lever and the throttle. Nor can you switch the shift lever and the rear brake lever. You just have to ride the bike they way it was intended. Besides, left foot does more work then the right foot. Good Luck
