Frank should be able to answer all of these questions, he seems to have installed quite a few of these.
There is a newer version of the G-Bar/G-link from Alston where the older one was based on the Airbar from Ridetech. They are similar but different. The canted bars are mounted differently and the shocks mount a bit different to the axle.
1) I have a PDF of the G-link install if you need it.
2) No it's not required, not as far as I know. There is a shock cross member that installs under your stock trunk floor.
3) Yes, you will need to install different shock mounts from your leafs. Or you could order a new narrowed rear with these all mounted up.
4) Not sure
5) I hear 3" tailpipes are tight, they would have to be custom made. Frank sells 2.5" tailpipes for the newer G-Bar/G-link setup.
I'm sure Frank will correct me if I am wrong.
Here are some good threads for reference:
http://www.camaros.net/forums/showth...highlight=link (G-link)
http://www.camaros.net/forums/showthread.php?t=145296 (Comparison with Prodigy Bar)