What goes here?

Okay so I recently purchased a a 2000 Mustang GT from a guy locally. I immediately failed smog and started finding little issues that always come after the purchase, atleast for me. So I desided to clean up the engine bay and return it to stock condition. I came across a few items that either look missing or misplaced.

First off: Located on the firewall right behind the upper intake plenum. It has two hoses with a wiring connector and it looks to be connected to the egr. My question is where does this get fastened down? It basically just rests up against the firewall right now and I'm sure it bounces around while driving.
View attachment 402639

Second: I found this wire located right below the engine bay fuse panel. The wire is solid white and from what I see goes somewhere below the fuse box or past it.
View attachment 402640

Third: I was looking at a few engine bay pictures and noticed something missing from the coolant tank. What exactly bolts up to the rear?
View attachment 402643

Thanks for the help.

The wire is just a white wire cut at the end and then capped off with some electrical tape. Its not a smooth wire, it has rib like texture that I have never seen before. It either ends at the fuse box or goes somewhere into the fenderwell. Where it ends, I have no clue. The rear piece from picture one only has one side to mount and it's plastic. Won't it get damaged on a hot head? The last one must have that metal piece missing because there is nothing near it now.