You need to be concerned with all frames, doesn't matter who made them! However, by 2009 WW had resolved the issues from 2004-2006 designs. Crawl under there and have a look, you never know what has happened to the trailer.
Get on the roof and check the corners with your fingers, if the wood "crackles" when you touch it it's been wet. If it's soft or collapses, it's been really wet and rotted away. Check around all the holes (A/C, refer, vents...) as well.
Look at the sides, trying to spot any gelcoat issues. It was common for all MFR's to have delamination from time to time.
Check the fit of all the doors, windows and hatches. Any movement in the walls with impact those.
Decide what you can fix, what you can pay to have fixed, and what makes it a walk away. Good luck!
Don't take life too seriously, it's not permanent.
06 Weekend Warrior FSC3200, Axles flipped, Bridgestone Duravis Tires
2005 Ford F250 PSD 4x4
07 Yamaha YZF450 White/Silver, 94 Husqvarna WXC610
2008 Polaris RZR 800, 2011 Honda CBR1000RR & one Goffin Cockatoo