Definitely take nappies, unless you are going to the hypermarket to buy some (do not know the cost there) because in the park they are very expensive. Powered baby milk - if bottle fed - in the hold luggage. Kettle, as you do not know the condition it will be in if there is one in your accommodation (lots of places in France do not have them) and it could be very old etc. Blackets (one for each, especially for the old child one you do not mind getting dirty - for sitting waiting for parades etc it can get very cold and and blacket can be sat on and wrapped around legs). Lots of film or large memory cards for camera, you will want to take loads of pictures. Spare batteries (and battery charger).
I also regularly take packets of pasta, just the easy make up ones (ie where you just add water & milk) as dd would not always eat much at the park (she wants to do things and eating is wasting time), so I would make them quickly back at the room while she was getting ready for bed. Not very healthy, but better than sweets. Anyway up type cup, dd would suck on take off and landing (she never had a dummy) to ease pressure on ears, also useful in cars - alternatively a bottle with a sports top so that drinks do not easily get spilt, you can take an empty cup/bottle on the plane and they will fill with water on board (you will get strange looks going through security because they will assume that you have liquid in them, so leave it where you can show them and if necessary just explain).
On rides remember the baby swap - others will be able to advise more as often only dd and me it was never appropriate. If an accident does happen the first aid place at DLP is brilliant, dd was ill one time with chest pains, the doctor spoke good enough English and her treatment & the facilities were like a private hospital (they gave her pain killers and we then took her back, she was OK the next day). Also, next door to that is a baby changing facility with feeding places I believe - if you want quiet.