Secondly rear legroom is almost nothing, i think in a review video the guy said there is about 2 inches of space between your knees and front seat.
You're incorrect. The new Impreza has been out for years and has the same interior dimentions as the new WRX. The back seat is considerably bigger than any Impreza has ever had, by a substantial margin. The 2015 WRX's rear seat has much more legroom than the 2014 WRX.