Gangs aren't all about violence. They are about making money. They typically don't mess with the general public because the general public is their source of income. They fight eachother all the time, this part is true. But they don't fight eachother for no reason. They fight eachother for turf to sell their product in. Want to get rid of gangs? The ONLY way you can is to decriminalize drugs and prostitution.
Half true. If you call the CHP about a crime in a major city they will refer you to that city's police dept. Its not a jurisdiction issue as much as it is a budget issue.