my town isn't really a city, but the crows here normally nest in any tall trees at parks, on trails, and in quieter areas. they normally eat things like trash from dumpsters, but i see them eating bugs and berries as well. they normally fly away when people approach them. people in the area don't really mind them unless they are ripping apart trash bags, because it is messy.
i do not remember ever seeing a crow hurt another crow, and the crows around my house appear healthy. i did see a crow/raven's leg in a parking lot once, but there were some feathers too, so it might have just been hit my a car. it might have been a magpie too, since we have a lot where we live.