Great topic!
You know, I'm not certain it is ever made entirely clear as to whether or not Astro has COMPLETE free will. He
does "break the robotic laws" here and there - like when he traveled outside the country to help the people on Sea Serpent Island - so maybe he
does choose to control himself.
I figured most robots would have obedience to the robotic laws programmed into them - it would be logical, in fact, if that were the law.
The reason I'm guessing that Astro DOES have some of that "protective programming" is because Atlas has the "Omega Factor" - which "allows" him to commit crime and harm humans in response to his own emotions and directions from others - this does NOT happen with Astro.
I don't know what to think about Blue Knight - maybe I missed something, but he doesn't hold back from harming humans either - I don't remember hearing that he had the Omega Factor, so I can't explained why he's decided to bring physical harm to humans, if he feels it's necessary in the fight for robots rights.
Then there's the many different "classes" of robots. A robotic machine that directs traffic or works in a power generating facility is presumably quite different from Astro, who is - for all intent and purposes - a sentient creature, albeit man-made. I mean - are humans being "cruel" to expect machines built to do particular jobs without days off, and "human rights?" It seems like "humanoid"/sentient robots are the only ones for whom "rights" would be an issue.
I mean, it makes sense to take care of a robot, to make sure it's operating properly, but in Tezuka's world, he seems to have a great many robots who are essentially "humans" who do the work
people used to do, only the robots are treated as slaves, and not human-equivalents.
I have often wanted to see a continuation of Astro's story where he actually becomes human (let's say Tenma or Elefun managed to clone/age Tobio's body and "download" Astro's memories into it). I think it would be fascinating to see how Astro would behave/react as a human.