All your other questions have been re Brilliance so do you mean her? If so then the answer is no unless you are in a suite when the answer becomes yes.
Some of my questions are generic but any that arent refer to the Norwegian Gem.
Yes - but not all - read the brochures.
If you don't state your cruise line/ship it's difficult to answer you.
Usually depends on size of cabin i.e. available space. In larger cabins or staterooms probably tea/coffee making will be there. You could always take a travel kettle etc. but that's a bit of a nuisance especailly if flying. Your cabin steward should be able to supply tea/coffee and hot water on request, no matter how small the ship.
The only RCI ship with kettles is independence - all others you call room service unless you are in a suite, and then you get a water heater. You are NOT ALLOWED to take on travel kettles as they are a fire hazard so please don't burn the ship down.
P&O have kettle/tea/coffee/biscuits in all their cabins.
On Fred Olsen, tea/coffee making facilities in cabins certainly on Balmoral and Black Watch. I believe also Boudicca and Braemar but not Black Prince.
Agreed, all Fred. Olsen ships except "Black Prince" have tea/coffee-maing facilities which are "topped up" twice daily.