At the end of The Last Stand, Xavier sent his mind to an unconscious patient, wake him up as Charles Xavier. And there are 2 theories follow that scene:
+ That unconscious patient was Xavier's identical twin which explain why he look the same.
+ There is no relation between Xavier and that patient. He looks the same because he used his telepathy to look so.
About his walking ability: He hasn't walked for decades, so his brain may forgot how to control his legs, how to walk ...
I really think storm and jean need to be re-casted, if they did they would slay.
They probably will, at first I was kind of bummed because I love Famke and Halle but if it means they're getting more significant screen time then I'm all for it.
)