Check the air quality reports when you are looking at neighborhoods. There are nice suburbs north, south, and east of the city proper - you can find mixed density and single-family zoned. (Mixed for the win). The main hospitals are in the central Oakland area and it is not difficult to get to them from almost anywhere, and it is not difficult to get downtown usually. Normal mid-sized city traffic. Hillman Center center is great and CHP in Lawrenceville is a regional magnet for your kid. (I am biased I work for them)