In my head it's like Constantinople.
But I'm flavoring the setting as late dark ages/early medieval so that skews my view.
3. (Big assumption here) The city itself is primarily separate by cultures and secondarily by social class.
That is about all I have so far.
Not sure here, vague concepts in my head of an old city populated by the cities elite and wealthy. It's been a melting pot long enough to have formed it's own city-centric culture where you are either 'of the City' or an outsider.
The old city surrounds two hills on one sits the temple district dominated by the temples of Memra and Miah-sha and all of their attendant gods and goddess's with only Nigal's temple rivaling then in size and grandeur. On the other sits the Mage Quarter, once the opulent home to the Narsin it became home to the to the few Mages remained when the Narsin left. Those mages that stayed eventually formed the Alchemists & Mages guilds. It is also home to those merchants that deal in magical goods.
Around all this are all the other things that you would expect to fine small cultural districts, various markets, homes (Of various quality), warehouses etc.
That's my take anyway.
Thanks for asking the question some of that stuff had to get out of my head........it was quickly replaced by more......oh the notions.
Edited: Because of the speed of thought.