Those strips that you provided are not canon and furthermore, they were created about 2-3 years ago. You know what is canon? The film Bardock: Father of Goku and the original Dragonball Manga which NEVER depicted Goku's mother and in which Bardock only ever seen his son once before he was sent to Earth to destroy it by the Saiyan officials, not his parents.
I know that you're going to say I need proof so I'll go ahead and post the entire movie Bardock: The Father of Goku. You tell me where in this film you see his parents put him on a ship to escape Freeza? Also, how the hell is Bardock present to put Goku on a ship to escape Freeza when it was he who provoked and swayed Freeza to destroy Planet Vegeta?
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Need anything else, let me know.
Also the depiction of Goku as a benevolent hero was the American depiction. IDK why people don't get this. In all actuality, Goku is a selfish character who only fights because, well, he enjoys it. Sure he'll protect his loved ones, but he really really isn't a hero. Gohan, is the hero Great Saiyaman. Actually, Goku has put the Earth in danger more times than he's saved it by letting opponents live and get stronger so he could fight them again.
Your comparisons all come from the American dub. In original Japanese anime and Manga his planet does not have higher gravity, the three villians thing is a stretch as Raditz came to Earth to bring Goku back, not to make it his home or conquer it. Vegeta and Nappa then followed only because of the Dragon Balls. He doesn't kill not because of moral high ground but because he wants to fight them again. Superman knew from childhood that he was an alien so what does Goku being older have to do with anything? He never swore to protect earth. He only swore to get stronger at all costs. He only fought the mad scientist and his androids, again, to test his limits and because they were specifically created to destroy him.
We can do this all day if you want. Fact is, Goku being a rip off of Supes is a stretch. The only super hero trope that Goku fits is having super powers, but I would argue that in his universe he doesn't have super powers as everyone and their momma has the same abilities. Goku's abilities come from martial arts and training. He wasn't born with them, he doesn't get power from a yellow sun, he didn't experience some kind of scientific accident, and he didn't take a serum. He's not a super hero. He doesn't fly around looking for petty crimes to stop and villians to beat. He only wants to test his limits and fight. Hell, even in Resurrection F, he asked Freeza to be his sparring partner and told him to leave Earth so that they could fight again. He spared Vegeta so they could fight again. He wished that Buu would could be back as a good person so THEY COULD FIGHT AGAIN. He had a chance to stop the Androids from ever being activated by finding the Dragon Balls but declined so HE COULD FIGHT THEM. See the trend here?