You also have to remember that Franklin and Namor were considered mutants during the late 80's and early 90's when everyone and their mother was claimed to be a mutant or connected to one in order to seem "cool" and capitilize on the budding popularity of the X-Men franchise. I mean, that was when Cloak & Dagger went from being "empowered by wacky drugs" to "wacky drugs merely kick-started their latent mutant powers", after all. By having the "anyone born with powers is a mutant" allows a lot of characters who may otherwise have been deemed as classic hybrids (like Namor) to be mutants. It also made Bullseye & Taskmaster hard to peg down.
Some of those NYX girls could be interesting, I recall one needed animal blood to gain her power. Imagine rushing into a firefight and she has to go, "okay, give me a kitten and a hammer".
I honestly doubt any writer wants to touch a perennial target of fanboy scorn than Leetch, who is usually considered incredibly annoying. Which means, yes, fans stereotype regarding a franchise that claims to preach against the evils of such. Irony!
I'd perfer Persuasion to Outlaw if they were going to go with a "new female member who was possibly over 18". Outlaw was just a hanger-on from AGENT X, whereas Persuasion fits the Runaway mold by being the daughter of Purple Man. Plus, she could also be on the run from Weapon X (she was last seen in their Neverland camp) and may even have Canadian agents chasing her to get her to return to some Alpha Flight (or the new Omega Flight) team now that many of the originals died.