LoadLeash Engine Brake

It will not. This style of the engine brake is what the industry calls a "weeper" engine brake, and it similar sounding to an exhaust brake.
When engaged, it holds an exhaust valve slightly cracked, slowing the engine by forcing the pistons to compress and suck air through a small opening, similar to the concept of blowing and sucking air through a narrow straw.
Compression release style engine brakes have an exhaust valve mechanism that it timed to the engine valve train to "pop" off the compression at a certain time which gives off the loud exhaust note, similar to when a pellet gun is compressed then fired.

Yes, but you must also use an exhaust brake to create the back pressure needed to allow theLoadleash to perform at its maximum efficiency.

Yes, you can. The Loadleash housing has provisions in place to allow the use of aftermarket head studs and nuts.
You can also use ARP custom aged head studs but must purchase the Pacbrake stud kit also made by ARP specially for this application. Part number P55127.

Yes, your performance tuner will have no effect on the engine brake performance.

As long as an exhaust brake or VGT brake is still present, an emissions delete will have no effect on the engine brake performance.

Pacbrake’s LoadLeash, used in tandem with the VGT exhaust braking feature, will result in a 40% increase in retarding HP when measured at the rear wheels (assuming 60 HP of drivetrain friction).

LoadLeash + VGT = 360RHP | VGT Only = 210RHP

Yes, ideally you should always run the exhaust brake in combination with the LoadLeash for it to perform at its peak.
Using the LoadLeash without the exhaust brake on will not harm the engine but it will not brake as hard as with the exhaust brake activated.

No, the LoadLeash, although an engine brake, gives off very little noise or exhaust note.

Yes, you can but it will not perform to its maximum braking performance.