There was a myth floating around in the eighties, and a friend of mine recently mentioned it, that you should always buy a new deck because a used one will have the previous owner's energy on it. First I told her, if she thought that was a problem, put a crystal on the used deck and set it in a sunny window. Then I told her I thought the story was concocted by publishers as a means of selling more decks, and that I got my Quantum Tarot used and it reads just fine.
I've heard the "must be wrapped in silk" one, and if I could afford silk scarves for all my decks... I do think they should be wrapped in something made of natural fabric, and most of my decks, except for those that came in really nice boxes that I display on my bookshelf, are wrapped in cotton bandannas that double as spread cloths.
As far as reading rituals are concerned, I really don't have a problem with other people touching my cards. When doing a reading for someone else, I usually ask if they're good at shuffling, and if the answer is no, I shuffle the cards myself.
Reading for myself, well, that's a whole nother affair. I lay my spreadcloth out, light a seven-day votive candle with St. Michael the Archangel on it, set my amethyst skull on the corner of the spreadcloth, queue up some music that goes with the deck I'm using... it's a very ritualized affair.
On the other hand, there are people here on the forum who can just throw the cards down with the TV on in the background and read.
I think a lot of the "myths" evolved because some people have a psychological bent where they're more comfortable reading if their cards are treated with respect, and a bit of ritual helps put them in the frame of mind they need to be in for a good reading.
I don't think Tarot reading or being psychic is a myth, although I'd be willing to bet that about 90% of professional psychics are frauds who are just good at cold reading. Reading Tarot is an ability that most people can learn, and I think there is some predictive value, although lately I'm steering away from predictive readings, but then, the future is not written in stone. I believe we create our futures by the choices we make, and if the cards show that the choices we're making are leading us down a bad path, then we can make different choices.