I agree that toward the end, Nick's scenes were kind of overdone. Not knowing much of Garth's other work, though, I didn't know for sure if he would make it through the book. Most fantasy authors seem to overfocus on their "normal" character.
Look at how many fantasies deal with "an average person from our world transported to a fantastic world", or "a person from a fantasy world who thought they were normal only to find out they have a greater destiny". First, it helps to have a "normal" person-character to whom another character can explain the rules/fantastic elements of the world. Second, the idea is usually that the reader will identify with the "average" person.
Kinda went off-topic there, but I think my point is that there's supposed to be "nothing special" about Nick.