Ditto as stated above plus:
Look under the TT too. Look for anything that looks unusual. Underbelly material fully secured. Wires not protected. Nothing bent or out of alignment. Etc.
Check axle rating against GVWR minus tongue weight and check tire load capacity. Manufacturers have been known to be undersized.
that is standard or an option against what is actually on your unit. For ex., we were supposed to have Alko brakes on ours but it had a no-name Chinese brand on it.
Check alignment and function of all doors and also the locks. Check operation of all drawers and cabinet doors. Slides and catches are often not working right. Do TV and antenna work okay? All windows open okay and window coverings are okay?
Check operation of running lights, turn signal and brake lights. Check operation of emergency break-away switch by activating when hooked up (try to pull forward). Also check operation of trailer's brakes (important). Take it for a test drive to test brakes at road speed. Took us over a year to get faulty brakes fixed that were faulty from new. An initial road test would have shown it.
Above all, don't let yourself get rushed or let anyone rush you. Once you get it home you can get so focussed on wanting to use it, you may overlook something or think it's not important and ignore it.
Here's a checklist that may also help:
As found on this site:
Doug's RV Checklist Page
One last thing. The tongue weight is light at under 10% based on the factory dry weights. Should be between 10-15% and avg. is around 12-13%.The tongue wt. and TT gross wt. will definitely go up by the time you are all loaded up for camping. Be careful on selecting the spring bar rating for the WDH. You may need 1200 lb rated bars. We bought undersized bars based on the factory tongue wt. and had to buy new higher rated ones. See if the dealer has a tongue scale. Also, at some point, I highly recommend that you go to a scale and weigh the TT and your TV and check the actual weights against capacities.
Good luck and happy camping!