I think certain 17" wheels could be fine - I think the design plays a key part - if the spokes come all the way to the edge of the rim, the wheels look "large enough".
I think there would be more of a positive reception for it in the U.S. market if the word "wagon" not be used.
How about simply just "Impreza/WRX Touring"?
I'll wait to pass judgement on the CVT for after I've driven it. With regards to packaging in the U.S. market, I can't see why it can't have the same suspension and drivetrain as the '15 WRX.