I felt the hiding in lockers was pushing the envelope a bit. Considering they've been able to track and outmaneuver people in the films from all kinds of distances. Suddenly one can't detect you 3 inches from its face? It's a tough sell, but it does add alittle fear to the mix.
Amanda being used as a host instead of being killed made sense to me though, given the circumstances. She was young, healthy, and easily captured in that instance. Prime candidate.