this is all very interesting! I do compare cards across decks, particularly for study purposes, and also when reading with a RWS based deck I will sometimes refer to the original RWS card. people change or leave off the strangest things! sometimes it offers some insight.
I do not think of my decks as animate beings with feelings and moods. I have however seen repeated readings on the same question (not "how can I improve that" but the same question over again) go wonky and dark. that just doesn't seem to work.
I like to read on many kinds of questions. I do not think this kind of thing offends the tarot, and it can stretch me. last week, I read cards about the development of condos that is supposedly going in across the street, much to the detriment of our parking, sanity etc (and I live in a converted warehouse right by the freeway and in between two sets of train tracks - hardly a desirable area!) it was a very clear reading, informative and concise.
anyway, my bottom line is this: the tarot doesn't *care* it just *does*. this is why it pulls no punches. if it did, it wouldn't be useful. it's easy to find someone to tell you what you want to hear. we *are* interviewing our souls, in a way. it isn't the cards themselves.
IMHO of course.