There is only one place that I would recommend you check for rust. Drop the tailgate and lift the hinged plastic cover over top of the hinges. Check your hinge brackets. That is structural. Because it is out of sight, it can get really bad without your knowing about it. I had a body shop cut and weld a new piece for me. Other than that, I would worry about what I see in your pictures.
Looks like pretty normal stuff except for the rear control arm bushing mount shot. It doesn't look too bad from the angle of the photo; but definitely check it out more closely, and then closely check the other side as well. These are well known rust problem areas on an Element.
If it is severely rusted in that area, the mount could break loose while driving. If one of those bushings comes loose, you are in for a wild and dangerous ride. This happened recently to another member here. Check this out:
I bought my 03 Element in November 2020. I wasn't looking for an Element, I didn't want an Element, but after I drove it and seen what great shape it was in and only had 82000 miles on it. ... I bought it. It didn't take long to fall in love!!! But all good things come to an end right? So, a...