Let me add my little voice to the recommendation for "In Search of Christian Freedom."
pater has been reading me bits and pieces of it. It has a very long section on the cruelty and unscripturality of disfellowshipping, as well as many other "core" doctrines. He won't let me have it till he's done, but I've managed to sneak it from him a couple of times. It's fascinating, and it really does help dispel some of those deeply buried nagging guilt. I have almost no "maybe they're not SOOO wrong" doubting thoughts after having read Mr. Franz' books, and for that, I thank him (and others that I've met here.)
Odrade