1. What is the purpose of this thing.. built in rear hatch prop or something? Im thinking of removing it so I dont need to make a hole in my new carpet for it.
https://i.imgur.com/kYutUDX.jpg
https://i.imgur.com/8aqdIZ5.jpg

2. I have this weird random warped bend behind the rear seats (paint missing/scratched cuz I picked at it), I heard storys about floor pans bending and cracking on cars without sub frames.. think this would this be what their talking about or could it be from something else?
https://i.imgur.com/tdoS3ml.jpg
https://i.imgur.com/6G5pmy0.jpg

3. Something weird I noticed was that the seam sealer in the trunk area is a very hard grey material, but once you get to the rear seats it looks like they used a different kind or something (first pic shows transformation) it has a very poor bond, has a bread dough consistency, falls off like nothing and seems oily.. i havent pulled the front carpet yet but it looks like they used this stuff all the way along the rockers and everything.. my parts car has the same deal. I was just going to pick it all off and reapply some eastwood seam sealer but I'm not sure if there is a reason GM originally did it like this.. maybe its a old school flexible seam sealer? I don't know - I just find it odd.
https://i.imgur.com/GyzdonU.jpg
https://i.imgur.com/sIBwsAu.jpg
https://i.imgur.com/bNg3pd5.jpg

 

The first bracket is for flat tire storage. Seriously, that's where you were supposed to tie down the flat tire while you had the spare installed and drove to the shop. I cut mine off.

The buckling on the rear bulkhead could be from body flex, but more likely some sort of hit from underneath when gas tank or something was installed.

Gm did seem to use different kinds of sealer in different places. The soft stuff is just sealer, the hard stuff is panel adhesive. The panel adhesive you want to leave alone unless there's rust under it. Soft sealer can be stripped and replaced, but no need to if it still seems to be in place to seal properly.