I have a PA12 but will offer what I can. I think the bungees you are referring to are used to lash down the rods you have in the horizontal rod holders. At least that's what I use mine for. There should also be a separate/loose bungee with a hook on it that can be attached to the boat and then attached to your mirage drive to keep the fins flush to the hull in situations where that might be desirable. Your boat should already have the steering drum upgrade but you might want to make sure your steering lines are taut and that the steering handle and rudder positions are true. I have rolled the boat into the water and then popped the wheels out. Doesn't work too bad but if you check this forum, you'll find that to be a much discussed subject. Just have to experiment and find what works for you. Hope this was some help. Still pretty new to this stuff so can only offer what I have discovered through trial and error. And error. And error.
Good luck and have fun.