There's all kinds of information out there - it takes very little effort to be informed. Readers who have gone to the trouble of learning about Tarot and their psychic gifts make unbelievably tremendous readers. Please don't let your ego get in the way. You really can learn something new everyday. So, if you're psychic, you're quite likely to be in a double bonus situation when it comes to being good at interpretation.
People are people.
They're going to do what they want to do anyway. So, please don't be judgmental. Just because one person's lifestyle isn't your cup of tea, doesn't mean that that person is wrong, stupid, etc, etc, etc. The Double Celtic Cross is used when doing mini-readings and regular readings. In both cases, I use only the Major Arcana part of the Tarot deck.