I am wondering if I will receive the room upgrade to business class room, then should I also get the complimentary breakfasts (I have only CC gold card)? According to their web-page business class rooms include the super breakfast buffet.
Most Radisson Blu properties will not provide free breakfast to Gold even if you're upgraded to a business class room. I've seen some reports on flyertalk of properties that do (none of them in Paris), but haven't experienced it myself.