Star wars theory
Light sabers are...a glamour, basically. Force users just trick people into believing they are real. Laser swords, plasma...no. It's all merely people being convinced that they're seeing and hearing and feeling something that isn't there, while some schmuck in a robe waves a metal handle around.
Star wars theory
Chewbacca is just a normal-looking human type guy. However, his species wears elaborate space suits that make them look 7 feet tall, and hairy. They also have respirators like Darth Vader to allow them to speak through their helmets. That's why they sound a little hoarse.
Star wars theory
Anakin's body was almost completely destroyed by lava. As an emergency measure, they took his brain and put it in another body -- a very pale, hairless one, undamaged by lava. But things didn't work out right re: the transplant, so they had to give him a whole life support suit.
Star wars theory
Most droids are actually controlled remotely by people working in big warehouses, like Amazon Mechanical Turk