> The kind of questions people bring to a tarot reader are of necessity the kind where there's no obvious way to determine facts.

If they are paying for a tarot reading, that means they believe there is a supernatural method of getting a factual answer. They do not believe you are just telling them your own personal intuition. You need to understand this if you're going to be taking people's money and not just playing a game with friends.

> Any reading that offers advice is opinion

Your customers will not understand this unless you explicitly state it.