2. It's probably a piece of cake with 2 people. You have the 4 bolts that hold the liftgate to the hinges, and another 4 bolts holding the hatch struts to the liftgate. You may have to remove the plastic trim on the hatch to get access to the bolts, but not sure. Either way, no more than a 40 minute job.
The interior plastic panels that are on the hatch are held up against the hatch with a "C"-like small clamp that is wedged in the panel. With time, these come loose, and fall out of place in the hatch, causing it to rattle incessantly.
To remedy this, remove the plastic panels on the inside of the hatch, and replace the metal clips that have fallen out (or see if you can re-use the same ones, but make sure they don't fall out again when you re-install the panels).