Both Rick Steves.com and Gemut strongly suggest using credit card insurance as being adequate for CDW. I think they would know if there were common issues/problems with doing so. It is difficult to evaluate individual claims about issues with credit card insurance posted online because we only get selected info. If you look online you will find postings of issues with CDW insurance coverage as well. You can print out the policy and carry it with you to show the agent, or have the card issue you a statement of coverage. In my limited experience refusing CDW is not an issue, they know Americans have credit card coverage. Whatever you do, don't forego the free credit card insurance to get plain (non-super) CDW with a very high deductible, there's never a justification for doing that.
This is pretty good http://www.creditcards.com/credit-card-news/car-rental-insurance-coverage-1273.php but remember to read for the international info mixed in with the domestic rental info which doesn't apply. Also, the primary insurance crap does not apply for international rentals. It will take a few readings to get the big picture.
For me: Medical My home medical insurance covers my family
Personal Contents in Car My homeowner's insurance covers
Liability The car rental agency always covers this, it should not be listed as a separate charge, since required by French law
Theft, Collision, Vandalism This is covered by the credit card, read for exclusions for length of rental, car type, etc. Note that vandalism or damage to glass is sometimes excluded from CDW but is not excluded from my credit card insurance
I can't image any value in a photo of a car rental person looking at a piece of paper as recommended 2 posts up.
As to the IDP, do a France forum search for this, already covered in other posts. I would be interested to know what the "I needed an International Drivers Permit...to rent a car in France" means, posted above. Required by whom? I'd be surprised if even 15% of American car renters in France bring one.