Is this where the Norwegian gem leaves from?

Yes

If the ship is advertised as "Leaving from NY Cruise port" then this is the place. All the major Cruise lines (Disney, Carnival, Norwegian, etc.) leave from one of the 3 buildings/ports that are part of this "Cruise port". The 3 buildings start at 92nd st and end at 95th st. Check your cruise boarding pass to know which building number you are leaving from. Also, I recommend using LYFT, Uber or any cab company to get you and your bags there! They are far from the nearest subway station and a bit of a long walk (3 blocks) from the nearest bus stop... And the side walks aren't kind to your suitcase wheels!

Yes bay 92

Yes the NCL Gem docks at 92 N River Piers , NYC

I'm not sure but you can check on the Internet or you can Google it

Probably as thats where we boarded the Norwegian Breakaway last week.

Yes. Both NCL ships at the docks.

Yes it in, also the breakaway