I am also a practicing Catholic. I attended a seminary in my youth but did not even approach ordination. Yet I have experienced many of the same issues and questions but not to the same extreme extent. The book is very well written but I do believe that the author would be more effective if he toned down some of the words he uses. Although I have a PhD, I found myself very frequently looking up words that either I did not know or that were used in a manner not familiar to me. This tended to make the reading a bit difficult (thank goodness for Kindle's built in dictionary feature).
The author has gone much further in his disagreement with the church than I would. Yet for the most part, He certainly has valid reasons. I too believe the hierarchy is "more or less" corrupt. I say more or less because I hate to lump them all together. Yet it is obvious that few live a day to day life style that mirrors what we know about Jesus; and, they certainly can be condemned for the manner in which the priest scandal was handled. Women priests? That would bother me but then I am very conservative by nature. I suspect I would eventually come to accept it.
All in all, I think this book is well worth reading but it would help for the reader to have at least a minimal knowledge of Church history (and I do not mean the grade and high school history taught in Catholic schools).
Also, if you too are a practicing Catholic, don't be scandalized. We all have to follow our conscience. His is maybe just different from yours and you may well believe him to be a heretic. But, he does have the good of our church at heart.