The leg on AF from CDG to Venice will be thrown it with no additional mileage to your TATL flight from the states. I think that generally if you can reserve Business seats TATL, there will be no availability problem with the CDG-Venice connection and it will most likely be in AF's so called business class for interEuropean flights, LŽEspace Affaires. This is actually just the first few rows of the plane with standard seats and standard pitch although the middle seat is blocked off and made into a tray table.

TATL, yes the AF seats are slightly narrower than CO, but they are flatter (still not horizontal however) and a 61" pitch vs 55" on CO. Personally, I think AF has a little more flair but, believe it or not, the food is better on CO. You'll be happy on either CO or AF.