I agree. Making them no-pvp prevents low levels from getting all cheaty and getting mega health and stuff, there's no reason to make them no-trade and no-auction, considering many of them can be bought from vendors. Also, you can right-click TCs to destroy them.
I wish we could sell the cards. I have so many polymorph mander cards, and I believe it would be a waste to just throw them away. I'm probably going to use them on weak bosses to give some more space into my pack.