If you fly with LH you can only use the LH lounges in the LH satelite. Security check is just before entering the satelite so changing lounges is not really recommended unless you want to waste your time in queues or arguing with french security personal why you want to go to another satelite.

The Senator lounge is CDG is one of the nicer SEN lounges: No windows and often full but nice food (also warm snacks), good selection of drinks (even real champagne) and free wi-fi.

As a 1K (*Gold) you are allowed to enter the lounge with one guest. No need to argue with any dragons.