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.