You can pull some extra mobs by going to these doors "http://wow.zamimg.com/uploads/screenshots/normal/426330.jpg"
If you jump on the right side you're able to get yourself stuck up a few feet, and cast something at them and should be able to pull the pats.
(I'll see if I can get a screenshot, but not tonight)
To get to the rest of the instance, once you've killed the last boss you can get to the other side of the room "http://www.ownedcore.com/forums/world-of-warcraft/world-of-warcraft-exploration/495695-other-side-of-tharbeks-room.html". You're able to bypass the door in there by putting a darkmoon tiger on the other side and just hopping off. This lets you pull another few packs of mobs, and you're able to get to the 2nd last boss. Highly doubtful you'll be able to kill the boss considering it hits for 70k pretty often, but there are the rooms with all the drakes ready for you to kill. The drakes are skinnable, the drop rate on the skinning book is pretty high, and they drop their leather. Drop rate on First-aid is also pretty high. I haven't seen too many greens so I can't really comment on that. You can however bring a chanter with you who can d/e the higher level greens (level 99 green did drop for us) and get the WoD mats early.