I got here too late to vote, but I would have voted for None of the Above.
Marseilles gives us dyes and has a decent strategic location. The barb city gives us ivory & food resources and also has a decent location (although it will require a lot of worker labor to improve). I'd definitely keep both of these cities.
We don't know where Paris or Tours are so we can't begin to judge whether they are worth keeping or not. In any case, I'm disinclined to burn any capital we capture. Once we know where and how Tours is situated we can make a decision on that city.
Short term, of course, keeping these cities is going to hurt our economy; but we can deal with that. Long term we'd be kicking ourselves if we'd raze any of these.