Everything you need to know is here:
http://www.citynightline.de/citynigh...sicht_en.shtml
The way CNL trains are configured (at least the ComfortLine single-deckers between Munich and Rome which is my 2 trip experience with them), the deluxe (shower) compartments are linked to economy (sink-only) compartments due to the bulge of the shower/bath (the shower compartment will not fit into the rectangular space of a deluxe compartment. The train is divided into sleeper cars (mix of 3 deluxe, 9 economy), regular seats and couchettes and may be all over the train depending on whether the train splits (or joins up) along the way.
http://www.citynightline.de/citynigh...ortline_en.pdf
http://www.citynightline.de/citynigh...ailansicht.pdf
Just a note that if you use 3 berths per cabin, the beds are apparently spaced closer to each other so it may be a bit more claustrophobic.
Not aware that there is a lounge car of any sort (depends on the route - see above). When you board, the attendant will offer you a drink which is a small bottle (1/4l or 1/4 of 3/4l) of wine or beer. You can fold up the bottom berth so it becomes a trio of seats.