Yes the furled jib is the forestay. There is no jib halyard or any way to tension the rig with a halyard.
Once furled, I use a shockcord ball tie through the jib clew to keep the jib furled when stored:http://cdn.hobiecat.com/digital_assets/2013-winter-sailing-pa-catalog-international_rev130906.pdf#page=31
Don't try stepping the mast with an unfurled jib, that would be a mess. The jib should be furled and wrapped up with the shockcord ball tie and the furler rope should be out. The furler will spool up when you unfurl the jib.
I'm running a lot of rake so my rig is loose. If you want the rig tight, you have to "walk" the rig tight using the shrouds. You need at least one extra shroud adjuster pin and ring. Pull down on the trap handle and slide a new pin one hole down on the side shroud adjuster. At this point the shroud will have two pins through its thimble. Add the ring and make sure it is secure. Then remove the upper extra pin. Go across to the other shroud and do the same thing. Back and forth walk it down until you are happy with the tightness.
You may think, why not just set the shrouds where they should be and attach the forestay? Well it's really hard to do with a tight rig. I even tried rigging a block and tackle and such and it was a mess. You pretty much have to walk the shrouds.
Before you tighten the rig up, be sure you remove the mast step pin first. It might be impossible to remove after tightening the rig. Same thing when putting the step pin back in, you may have to loosen the rig a little first. That depends on how much rake you run, the more rake, the harder it is to get the mast step pin in/out.