Marseille is one of the best places to try seafood in France

I have heard that as well. The little that I had was good.
I haven't seen that show. Nice might have some bad areas like any major city but I didn't get the same vibes as I did with Marseille. I'd say you could skip Marseille and not really miss out on anything. There are much better places in Provence and much better along the Riviera.