* do I need 2 16ft. lenghts of shock cord for the front?
* does it start and return to the same side? run thru block on other end?
* do i need to drill the rivets and remove the end cap to route? try a snake?
Yes, Yes, & Yes.
Drill out the rivets that hold the end cap in place and you will see how the system is routed. There is a single pulley and a single tie-off point on each end of the crossbar. You tie off, pass the bungee through the crossbar to the pulley on the opposite side, and then back out through the end cap on the side where you started. Repeat for both sides.
The other option is to add another grommet to the tramp and lead the crew's trap line to the shroud in the same way that it's done for the skipper.