You took so much effort in writing a long post, i think you are too obsessed with city.
Brother, spend a few bucks, buy a measuring tape, visit the 4 cars dealerships and you will learn that Yaris has the biggest cabin amongst City/Aspire/Saga.... City is bigger than Alsvin and smaller than Yaris, Alsvin is bigger than Saga but Smaller than Yaris and City.
Please, you have evey right to praise a car but please keep facts correct. Yaris is not cramped, if it is cramped then city is Super Cramped and definitely smaller.
Yaris is not selling just in Pakistan, it has also outnumbered Toyota Corolla in Saudi Arab and certain other countries aswell. Did not do well in India because it was priced much higher than its competitors due to having 7 airbags and features which are not a priority in poor consumer countries like India...
New City will definitely be a good competition, the only factor would be pricing, the car with the cheaper base variant will be the winner in number of sales.
As for shape, now Yaris has been well accepted in the market, leading sales for consecutive 11 months leaves no question of being a not so good car. It has been reported offering upto 20 kmpl on the 1.5 variant. Lets see what happens next...