The Long Beach, CA area is a strong rental market. I think its one of the few markets where there are more renters than there are homeowners (but don't hold me to that bit of info).
There are many different areas in Long Beach from affluent to gang ridden. The 2nd Street and Naples area and others close to the waterfront are nicer areas. As you move north and to the west the areas get a little rougher.
The economic metrics you mention don't look like a good deal. Net out the rents and you're looking at a retail price for units at around a 5% CAP. That's how retail buyer buy property.