Step 57 & 58 instruct you to kill Luzran and Knucklerot respectively. At this point in the guide I was level 14 and had no way of attempting to kill these level 21 elites; even with a group, I would be unable to help.
Also, this step tells you to use the group finder, which is not a feature implemented in Burning Crusade.
Step 166 instructs you to go to Zeb’Nowa and complete some quests there. One of the quests (Step 173) tells you to kill Kel’Gash, who is a level 20 elite. This is a group quest, however the guide makes no indication that this is the case and leads you to believe it can be done solo (which is definitely not the case at this stage, I was level 18 at this point).
Hopefully these issues can be fixed!