Oh man, that's one hell of a process to go through just to find out it was a loose plug. Big karma points for sharing with us here, hopefully it helps someone in the future.
Welcome to the forum.
It's always smart to research before buying, but if you spend enough time on the internet, you'll find doom and gloom about just about every make and model. At the end of the day you should pick the ute that suits you best.
I bought my 2009 D40 RX because I got a low...
My D40 had Michellin Latitude Cross's on when I bought it. They're great on bitumen and gravel, and they've handled the limited offroading I've done pretty well. I think they're pricey though so I'll probably be shopping around when it comes time to replace them.
When I was Navara searching, I noticed wear and tear on the plastic around the window switches was pretty common place (that and the stereo buttons). I'm no expert but I on't think there is anything you can do to freshen it up short of replacing the plastic surround.