I haven't been in the cigar lounge for a long time (only in Concourse A) but iirc they are complimentary. My information may be out of date though. Will report back if I am in there in the next few days.

Showers - as the F meal service is dine on demand, then this all depends on when you want to eat your pre-arrival meal. Shower times are pre-booked in 30 minute slots, first come first served, so you can choose when you want it. If there's 2/14, they may reduce the water load though, so you should check if it's possible, but I don't forsee many problems, except that the cabin may end up going full in case there are last minute bookings and op-ups.

However, I have yet to see a 14/14 cabin where everyone used the shower