Charles De Gaulle - Changing Euros

I was thru there in June and July of this year and saw several of the "Currency Exchange" booths, also known as "Rip Off City". I have never used their services but I would suggest that you approach one of them and see if they will convert for you without charging any fees. If they want to charge a fee, it is up to you if you want to pay them or wait until later. You did not say where you are headed from CDG but if you are headed to another country that uses Euros, I would wait and go to a bank there where I am sure they would convert them for you.

I am certain that there are any number of merchants at CDG that you could buy something from and get change, they may not be happy about this if the purchase is tiny.

Why do have a supply of 100 Euro bills? Ask for an amount that is not an even hundred at the ATM.

First question: We will be taking a taxi from CDG to Paris. No plans to travel outside of France.
Second question: We were able to get a good exchange rate at a service here in Bellingham, but they were only able to supply 100 euro notes.

I suppose this is the answer for all those who say "I prefer to have some cash in my pocket when I land, rather than have to find an ATM". That cash is not any good if it's too big a denomination to use. I would think a cab driver will take it (though he may try to short-change you), and if not, I would bet he'd come in your hotel while you break it at the desk. The cost for getting your cash out of an ATM, if you have an account with any of the non-fee charging banks repeatedly mentioned here, would be about 1/2 of 1%, as they convert at that day's interbank rate.

I would not expect any problems changing an €100 note. If your taxi fare is €30-€40, that is a large part of €100, so he should be able to change it.
Equally a restaurant bill for two will be a substantial portion of €100, so they should have no problem as they have a till full of smaller notes from other customers. The only time I had a problem is with an €500 at lunchtime at a restaurant in Italy, but I think he was just making a fuss as he didn't want to lose his float so early in the day.
Cash machines usually dispense €50.

as noted, you won't have any problems using 100s for things like cab in from the airport (50 or so Euros), restaurant bills etc and you can get smaller bills when you use ATMs. 500 Euro notes are almost impossible to use, but 100s are only slightly aggravating.

If you withdraw 100€ or 200€ from a CDG ATM you would get smaller bill than 100€ notes.

yeah you can burn through 100 euros per meal easy, so beware.

Otherwise as noted, ask at some bureau du change if they will do the deed, or change one or two at your hotel.