Now that you mention back-seat passengers, I do vaguely remember hearing something scrape on a "shortcut" I took, followed by my friend in the back complaining that he'd hit the headliner. Collapsed springs may explain a few things about this truck.
Speaking of hitting heads on things, I installed the new struts today, and I'm loving the difference. The bottom corner is up by 7 3/8", and I can walk under the hatch without hitting my head on anything. I am well clear of that damn corner, which is worth the cost on its own. I only clear the plastic trim by an inch or two, but if I get another 2-3" from fixing the suspension, that'll be plenty.
The only problem I've run into is that the ends on the struts have a little less range of motion than the old ones, and I guess the angles are a little funny on the upper ball stud mounts, because the top joints ran out of travel before the bottoms were in position. I was able push them the rest of the way without obviously bending anything, but, yeah, that ain't right. I'll go in later and see if I can file a little clearance into them. If that doesn't work, the ends are just screwed onto the struts, so they should be easy to swap out. Maybe the plastic ends have more range of motion. That would make sense--I ordered the metal ends thinking they couldn't go wrong, so of course they'd be the one thing that did.
I used SE244P110S10-W (x2) from liftsupportsdepot.com.
Side note, that rear hatch is a heavy bastard.