Oh, nice. I will update my version a little at a time to bring it mostly in line with the original. Filling in names, put in some extra decor, that kind of things.
As for the backstory:
I feel that Cesar should rightly be a night watchman, but then it overlaps with any covert action Ben might have planned. It also prevents him from getting to the 'crime scene' the morning after. On the other hand, beings night watchman might be a great excuse for being up and about at night.
After some thought, I think night watchman makes more sense.
Regarding his home, I would think the family definitely had an estate where it's holdings were and where they lived most of the time. However, I also like the idea of a physical reminder within the city walls. Perhaps a nice Villa for when they visited/had business to discuss?
Also, just to be clear: both identities are forged. He symbolically burned his belongings and papers when he embarked on his new quest. If pressed, I would say Ben is the truer of the two identities.