The thing about not being able to go inside a district unless you reach the proper level is clearly bullshit. They clearly stated that there are clients passing through the town, so people CAN and DO go to higher districts (how could Urara make their jobs otherwise?)
There should be also people WORKING in the higher districts: who provides for trash collection and cleans the streets? For some reasons I don't think it is the first Ura...
The only thing that COULD be forbidden, is for urara to set shop in districts higher than their level; anything else is a nonsensical plot device.