LOL, welcome to dealing with Fiji Airways. They are very small, and not the most modern or easy to deal with.
If you booked all the way through on one itinerary overseas/domestic you should be ok on luggage weight since they have to take whatever you check even on the small plane (if you just booked a domestic flight, lol good luck if you have bags). Though I did still get shaken down once flying from Taveuni back to Nadi when the agent claimed they couldn't verify my reservation so I gave them the $40 or whatever I had on hand and got on the plane. Bring printouts or screenshots of all your tickets/itineraries just in case.
