club balcony suites have a larger sink and shower. Plus some other amenities, like one free bag of laundry (small bag), a bottle of wine/sparkling wine in your room, extra latitudes points maybe, and two nights of goodies/treats delivered.
I'm not the right person to ask about packing, but... international bags can be heavier if I recall correctly and each person can usually have one checked bag included.
No self serve laundry on board, you can send it out.