Some other comments from the pictures so far.
It does look like a lot of new parts were used, so you did get at least some of the stuff.
What height is the suspension lift? If you said, I forgot, but the rear differential vent was not extended, nor does it look like the parking brake cables were.
But the cables might be due to trying to snake around the dual exhaust. Dual exhaust systems are a royal pain on Broncos.
As you can see, the left side exhaust is extremely close to all the goodies. Fuel lines, wiring, brake lines. All important things.
If the heat is effecting the fuel temperature and there is not a return line you could still get trouble from that I would think, depending too upon where the fuel pump was placed.
Most dual exhausts are like yours, but a clever installer could have kept the mufflers and pipes farther away from the frame rail and all the tubing. And the installer could have done something about the parking cables and vent line.
Wondering how the front and rear brake hoses were handled? Maybe they're stock length too, which would be too short for a lift of 3.5" or more.
So as you get time, and can crawl over, under and around the vehicle, keep the pics coming. So far they're telling us a lot. Just not the whole story yet.
Paul