I think Marvel's premier heroine should be someone who is in a title of her own. Sue Richards has always been thought of as part of the Fantastic Four, and yes, by that token she ought to be the first lady of Marvel.
However, I do think that Ms Marvel (yes, with that name) has the potential to be Marvel's premier heroine and Wonder Woman equivalent. I never really thought Storm was that, because she is always part of the X-Men.
In the late 70s/early 80s, Spider-Woman was often marketed as the premier heroine in all of the adverts and promotional material. She-Hulk has that potential too, but both of these are usually just thought of as female equivalents. Since Carol is always the one who is around and more popular instead of Captain Marvel, I think she has surpassed her namesake as a stand-alone heroine instead of being seen as a female equivalent.
Ms Marvel's classic costume is iconic like Wonder Woman. They should stick to that. Also, Captain Marvel sounds more like a man's name (it has been usually associated with one). It never seemed to fit on Photon and it doesn't fit with Carol either. Ms Marvel is just more attractive and feminine. It's often almost pronounced like Miss Marvel (or could be mistaken for that instead of Mizz Marvel) and therefore has that attractive beauty queen sound like Miss America/ Miss World or strong bodybuilding sound like Miss Universe. The name "Ms Marvel" almost tells the world that she is Marvel's premier heroine. It's like she's won that honour out of all of the Marvel women to become Miss Marvel. That's why I think Ms Marvel is an infinitely better name than Captain Marvel for Carol.
And that's why I also think Ms Marvel sounds better than Warbird or Binary. Ms Marvel has that "Superman" type sound, just like Iron Man also conveys. Iron Man goes beyond just being a man who is made of iron, but has all the connotations of strength and other associations with the Ironman triathlon, which is why Iron Man sounds better than War Machine.