Unless you buy an Airstream trailer you can expect problems and the need for a short shakedown trip before making a long vacation or other trip.
I would assume that the factory made mistakes and go through the trailer now before you take it back to the dealer and check plumbing fittings and battery hold downs and everything else both inside and under and around the trailer. I would even check the roof and any seams and be sure they were caulked or bedded properly. Run the furnace and the fridge and the water pump(s) and turn on all the lights, and anything else.
I use to deliver $150,000 sailboats in the 1980's to the Virgin Islands for the charter trade and 100% of the time I needed to make repairs while underway as the broker's people had not checked everything and the buyers had not bothered to do a shake down cruise, which is often the best way to find problems. Instead I would find them 1000 miles from the nearest landfall.
