That wire's gotta be a "safety catch." Definitely not a ground wire. If you look on one side, it's like a clutch/cable brake end. I know this would be a good idea after seeing how poor those previous gen band clamps worked. Probably why whey also changed to a "balled end" design. But chances are they will be cut and never re-installed by most people swapping out axlebacks unless they have their hands on the crimp tool for the wire or come up with another solution.
The weird looking h-pipe I'm guessing is for flex? The pic isn't big enough to tell if that's actually a spring or flex pipe.
The flex tube H pipe is simply an expansion/contraction point for the exhaust. It helps alleviate the stresses on the headers as they heat and cool. with out that it would be more likely for the headers to develop cracks.
yea the 2 piece ds was the first thing i saw could be changed for improvement. next thing i saw was that they added resonators right after the h so im assuming the 5.0 is louder than the 4.6. also looks as if they made so that the h pipe could be removed or swapped out without touching the cats. guess they dont want people removing those anymore lol.