Nose high comes from trying to get as much travel in the front as possible. Can only go up so far, then you gotta move the wheels down at ride height to get the desired up travel. Keep in mind that desert trucks are generally set up with ~60% of their total travel in the up direction while crawlers are usually set up with 60% or more in the down direction. The rear is much easier to get the same travel out of w/o going as high. Not saying it's the right way to do things, just that it's what tends to happen with amature builders.
Then there's the "Trust Fund Truck" crowd who tend to concentrate on the front and leave the rear stock.
As to the bolted sections, that's left over from some trucks being built with a joint like that at the top rear of the cab. I'm not completely sure they need to be there, but the design does have a following. In this case I think it is misapplied b/c the total structure is not as long as a truck.
Dig up the pics I posted a while back of the cage Total Chaos did in a K5. It doesn't have those bolted joints.