"A question slightly off topic, but what kind of space in the crew rest areas do the flight crews have?"
Most have two seats outside the cockpit, a few with a hard bulkhead vs a cargo net have six seats, and some have a "Crew Rest Facility" which has two bunks. The crew rest facility is only used in cruise because when it is expanded for use it blocks door L1.
"And how many crew members do you take when flying across the pond?"
Depends, if less than 8 hours block time two pilots, 8-12 hours three pilots, 12+ hours four pilots. ANC
-SFS 4, KIX
4. Some legs like EWR
only two are actually required but we always fly with 3.
"Also, are the three dark red handles on the top panel the fire bottle levers? "
Fire Levers, used to shut off fuel, hydraulics, air, and electrics for a given engine.