uncomfortable truck

[K9sH3]

Whaaaat, sounds like you have a lemon. Keep all records of repair and use them to your advantage. I had a POS once in a Dodge I owned and after they got tired of all my biatching. I ended up with them buying it back.
I have had probs with the H3 also, not as bad as yours; I am one my second windshield they seem to break to easy, I have had two door handles break, The AC on blew on max cold, no matter what the fan was set to. And like you I have sunrood issues, mine leaks it goes in for the third time this Wed. Somehow whenever it rains and it is closed I still get water in the drip area, and the tiny drains don't drain and the water makes its way down along the dash or through the mic right above where you sit.
But I still like it, and I suppose I am the lucky one here out of all of us, I fit in mine just fine.
My only real biatch is that I wished they have more than one choice of power for it, maybe a turbo diesel or something.
Good luck with your H3, keep going back to your dealer and keep the pressure in them.
My dealer is to far away, I have a local GMC dealer take care of mine.