My only advice is to check beneth all trim, door panels, rocker panels, rer gates etc. These things (Fords Chevies and Dodges) have such spotty "paint on" methods that every so often a unit will come through where all the weep holes and drainage holes are clogged with paint and the damn things start rusting out (inside of wheel wells, bottoms of doors etc). Trailblazers have always had an advert base of a "macho" off road kind of vehicle and that always mens retained mud and moisture.
Also, if its got these foam sound dampening things on inside wheel well and door corners (especially down facing ones, )remove all that crap cause it will also promote rust by not letting it drain quickly. (I have no idea what truck makers are thinking about).
Im not familiar with the performance of your chosen unit but Id be watchful of any maintenance records. Its amazing how a bit of good maintenance can extend a vehicles usable life. Especially one that sells itself as an OFFROAD wagon
Just some ideas based on my experience with trucks.(Mostly all F250's and 350's)