I'm not sure of the comic book stats, but she's basically superior to Thor since she can do anything he can, PLUS she has energy absorption and projection abilities as well. The energy projection abilities also match one of Iron Man's main abilities. She has strength that excels Captain America. And I'd imagine she could probably challenge the Hulk, even if the Hulk is stronger in terms of brute strength. So, Whedon may have simply meant that writing for a character like Captain Marvel is that much harder because it's difficult to come up with credible challenges and threats. How do you contain such a powerhouse without making them look stupid or ineffective?
I agree with your post, but in terms of all that nerd stuff you were talking about: In the comics, Thor is definitely more powerful than her. Well, he has more
strength than her, while all their other powers are more comparable. Hulk is technically stronger than her, too (he and Thor are tops in terms of sheer strength). However, as you mentioned, her other powers kind of give her a special edge, because she can absorb enough energy to become as powerful as a nuclear bomb (which she just about did in a recent issue).
Where it gets tricky is that MCU Thor is notably de-powered from his comic book incarnation, so I think if Carol's NOT very de-powered in her MCU translation, then she could end up being the most powerful hero they've introduced. Now, we would normally assume that they
would de-power her slightly for the same reasons they did with Thor, but Kevin Feige did introduce her as "
one of, if not THE most powerful hero in the entire MCU," which has me thinking they might not. Either way, she's definitely more powerful than Cap and Iron Man, no question.
But yes, I do believe this is what Whedon was talking about in that quote, which as I mentioned before, would explain why Thor kinda got the short end of the stick in Whedon's
Avengers script. That said, I still hope Whedon at least writes
Infinity War, because that will be the first time in which writing for these ridiculously powerful heroes won't be a problem at all since the threat(s?) will have gotten so huge that even characters like Thor and Cap Marvel at full power would legitimately struggle to win.