I can't remember exactly how the boom was rigged but I can tell you that the forward cleat is part of the mast rotation limiter. A line should be tied to the boom, then through the rotation arm on the mast (mine had a small pulley on it - but it's not necessary), then back to the cleat on the boom. The length of this line dictates how much the mast is allowed to rotate. The bunji inside the boom is for the mainsail outhaul but I can't remember exactly how that is run. However, pulling the ouhual line should take the sail out to the end of the boom. If you release it, the bunji helps pull the sail forward (toward the goosneck) - yep, for downwind to make the sail fuller.

The small block on the side of my hull is for the skipper's trapeze bunji. Normally this bunji would run straight accross the boat under the trampoline through grommets in the trampoline. However, when I got the replacement trampoline, it was missing these grommets. I ran the bunji through the main beam instead (that's what you see in that picture). The crew's trapeze bunji should simply run through the main beam. I installed small hooks on the ends of these bunjies so I could connect and disconnect them at will.

Yes, main traveler should also function as main sheet ... i.e. continuous line.