Steel has barely been relevant in years.
He could be again. Just a matter of a choice. He got his own title, and a movie, even though the movie bastardized the source material. There are black characters created in the 1960s that are quite popular today, including Black Panther--a perfect example of my point. I wouldn't want an actor of a different race to play T'Challa for the same reasons.
So what? They were brand new, there were two female characters, and they were successful. That was a choice of the creators to make them white. The point is that new characters can work, and the Incredibles are a perfect example.
Miles worked because there's still 616 Spidey around. Terry barely worked.
They both worked, and you touched upon why--the original characters were still around. Terry was a brilliant idea and the reason was because Bruce Wayne was there. He wasn't so much a replacement but a successor.
As for Miles, it's the same idea. On his world, Peter died, but the main Peter is still alive, so they didn't replace anything, they didn't kill anyone, and all they did was create a new character, that was successful. He showed there is room for more.
She's a Mary Sue as much as Rey, if you want to be like that.
Do you watch Game of Thrones? Arya is a big time hero. I think she's much different than Rey. Much better written. Rey feels forced, pardon the pun. Arya is more like Xena or Wonder Woman--a hero that trained her whole life and used that training for the greater good. She's not the biggest, or the strongest, but she is the most motivated and skilled. They didn't have to weaken a male character to make her strong. They didn't have to prove her worth. They built it up. Arya is a brilliant hero, and an original character.
New heroes very rarely sell. That's historic fact. What's racist was making them all white to start with.
You seem to have a misguided definition of racism. And history has shown you are wrong. Every hero was new at one point. And there are plenty of non white heroes that have lasted over 50 years. That's the true historic fact.
No, because when it happens the other way around it's the less advantaged getting some respect.
This is wrong on multiple levels. Not only is it an attempt to justify racism, it is the exact opposite of respect. It's pandering and making a statement that X minority can't succeed on its own without some liberal white savior patting them on the head and giving them a token change. Respect would be to add new heroes and characters to the mix.
Usually its' just because they couldn't be bothered.
You have evidence of that? For example, do you have access to a comment by Bob Kane that Batman was white because he couldn't be bothered to make him black?