Originally Posted by Electrix
McAvoy can do many accents so you don't have to worry about that. He did American in Wanted and English in Atonement.
Height isn't that much of an issue to be honest. If they need him to be taller they'll use camera angles etc. In the event Charles loses his legs in this height won't matter at all.
Well, height wouldn't be that big of an issue, but if they're on-target with the small details (Xavier being 6 feet tall), I believe that they'll be more likely to work out the larger more important details.