The Mighty Eve Tushnet (whom you probably have read already) has a top-notch post on intercession of the saints.

She speculates that Protestants wouldn’t have a problem with a prayer to an angel, but all the Protestants with whom I’ve ever discussed that topic condemn the idea out of hand. They say that prayer should only be directed to God (usually trying to base this on the first commandment). It underscores to me that most Protestant doctrines are ultimately dependent on a nearly Islamic version of Christianity in which the emphasis is placed not on the incarnation, but on the great chasm between God and man, which is primarily bridged by a book. There are few rituals to supplement the book, no universal organization, very few people to whom one can go for spiritual help and (usually) no reward whatsoever until either death or the end of this world, whichever comes first. ‘Tis a great and good thing to be Catholic!