If you gather all the mistakes that have been discovered here at first glance and still want to stick with the architect, then you don't deserve any better.
Regarding the missing staircase to the penthouse floor: that is not a mistake, that is a feature. Since you can't see anything out of the windows anyway and the balcony cannot be accessed, he figured no one would ever go up there anyway. So the staircase was consequently left out, which also saves a lot of money.