Solve the first two points (make city living vastly less expensive and increase the quality of the housing) and a lot of other problems go away.
Bothered by homeless people sitting on the street? A lot of them would rather be in a living room. Got mugged recently? While it doesn't excuse the mugger's behavior, they'd be less likely to commit the crime if their rent was dramatically cheaper. Don't want to listen to your neighbors arguing? Changing up the walls in your apartment building can help a lot.
Bothered by homeless people sitting on the street? A lot of them would rather be in a living room. Got mugged recently? While it doesn't excuse the mugger's behavior, they'd be less likely to commit the crime if their rent was dramatically cheaper. Don't want to listen to your neighbors arguing? Changing up the walls in your apartment building can help a lot.