Lots of rattles.
Transmission doesn't shift right.
Passenger window seals leak.
Rear hatch is a guillotine.
4WD is really 2WD. This vehicle is not meant for real off-roading. It is only designed for snow covered pavement.
The seats would be better suited for an elementary school bus. They are hard and small.
The gas mileage is atrocious.
If you want to off road buy a Bronco. Explorer 4 wheel drive is meant to get you out of snow on pavement not to rope cattle on the mountain range.
This isn't much of a review, but I haven't noted any of the problems that you mentioned. No leaks, no transmission problems, and I think my seats are great, especially with the adjustable lumbar support. No rattles, either. Your rear hatch sounds like the pneumatic supports are shot. They cost about $8 apiece and it takes about 10 minutes to change them.
Regarding the 4WD, while this is not a Jeep Rubicon or a '79 Plymouth Trailduster, it does have a 2-speed transfer case (assuming you got the 2WD/4WDLO/4WDHI option, and not the AWD option) and is at least based on a truck frame. Not, it won't blast over boulders, rock crawl, or go through 3-foot mud holes, but it will at least handle primitive roads.