My friend swears by it. He claims the key to understanding Quantum is to live by the code of Liboff.
I don't learn anything by reading though, I learn by working problems. The best way to learn for my kind of brain is Griffith's QM book, because he grades the problems by difficulty, and solutions manuals are available for his problems to check the work.
The Schaum's outline for Quantum is excellent as well. It has a lot of typos, but they're pretty easy to spot. The problems are fairly involved and generally a lot more complicated than anything you're going to see on the GRE.
As for your other question, about using qualifier questions as prep for the gre, I say, avoid them. Quals are usually more time-intensive than the quick-jab work of the gre.